Method and system for organ positioning and stabilization

ABSTRACT

This invention provides a system and method for positioning, manipulating, holding, grasping, immobilizing and/or stabilizing a heart including one or more tissue-engaging devices, one or more suction sources, one or more fluid sources, one or more energy sources, one or more sensors and one or more processors. The system and method may include an indifferent electrode, a drug delivery device and an illumination device. The system&#39;s tissue-engaging device may comprise a tissue-engaging head, a support apparatus and a clamping mechanism for attaching the tissue-engaging device to a stable object. The system may be used during various medical procedures including the deployment of an anastomotic device, intermittently stopping and starting of the heart, ablation of cardiac tissues and the placement of cardiac leads.

CROSS REFERENCE TO RELATED APPLICATION

This application claims priority to co-owned U.S. Provisional PatentApplications Ser. No. 60/261,343 filed Jan. 13, 2001, Ser. No.60/263,739 filed Jan. 24, 2001, Ser. No. 60/282,029 filed Apr. 6, 2001and Ser. No. 60/286,952 filed Apr. 26, 2001, and is a continuation ofapplication Ser. No. 09/879,294 filed Jun 12, 2001, now U.S. Pat.6,447,443, the disclosures of which are incorporated herein byreference.

FIELD OF THE INVENTION

This invention relates generally to a system and method for positioningan organ, and more particularly to a system capable of positioning,manipulating, stabilizing and/or holding a heart during cardiac surgery.This invention also relates to a positioning system and method thatincludes monitoring one or more chemical, physical or physiologicalcharacteristics of a bodily tissue or fluid during a medical procedure.

BACKGROUND OF THE INVENTION

Coronary artery disease remains the leading cause of morbidity andmortality in Western societies. Coronary artery disease is manifested ina number of ways. For example, disease of the coronary arteries can leadto insufficient blood flow to various areas of the heart. This can leadto the discomfort of angina and the risk of ischemia. In severe cases,acute blockage of coronary blood flow can result in irreversible damageto the myocardial tissue including myocardial infarction and the risk ofdeath.

A number of approaches have been developed for treating coronary arterydisease. In less severe cases, it is often sufficient to merely treatthe symptoms, with pharmaceuticals, or treat the underlying causes ofthe disease, with lifestyle modification. In more severe cases, thecoronary blockage can be treated endovascularly or percutaneously usingtechniques such as balloon angioplasty, atherectomy, laser ablation,stents, and the like.

In cases where these approaches have failed or are likely to fail, it isoften necessary to perform a coronary artery bypass graft (CABG)procedure. CABG surgery, also known as “heart bypass” surgery, generallyentails the use of a graft or conduit to bypass the coronary obstructionand, thereby provide blood flow to the downstream ischemic hearttissues. The procedure is generally lengthy, traumatic and subject topatient risk. Among the risk factors involved is the use of acardiopulmonary bypass (CPB) circuit, also known as a “heart-lungmachine”, to both pump blood and oxygenate the blood so that thepatient's heart may be stopped during the surgery, with its functionperformed by the CPB circuit.

Conventional CABG procedures are typically conducted on an arrestedheart while the patient is on CPB. The CPB circuit provides continuoussystemic blood circulation, while cardioplegic cardiac arrest enablesmeticulous anastomosis suturing in a bloodless, still operative field.In the majority of patients, obstructed coronary arteries are bypassed;for example, with an in situ internal mammary artery (IMA) or a reversedsegment of saphenous vein harvested from a leg.

Segments of other suitable blood vessels may also be used for graftingdepending on availability, size and quality. In general, the body hostsseven potential arterial conduits, the right and left IMAs, the radialarteries and three viceral arteries, one in the abdomen, and two in thelower abdominal wall, though the latter may be quite short and aregenerally of limited usefulness. The viceral arteries include thegastroepiploic artery and the splenic artery.

The left IMA is best used for bypass to the left anterior descending(LAD) coronary artery and its diagonal branches. Whereas, the right IMAmay be used for bypass to selected vessels more posterior such as thedistal right coronary artery (RCA). The right IMA may also be used forbypass to selected marginal branches of the left circumflex coronaryartery. A segment of radial artery harvested from an arm is generallyused to revascularize the posterior surface of the heart. The rightgastroepiploic artery may be used to revascularize almost any artery onthe surface of the heart. It is most commonly used for bypass to thedistal RCA or the posterior descending coronary artery. In unusualcircumstances the splenic artery is used to revascularize posteriorcoronary arteries, but it is long enough to reach the marginal branchesof the circumflex coronary artery.

Surgeons will generally complete bypass grafts to the following coronaryarteries in a patient undergoing multiple bypass surgery in roughly thefollowing order: posterior descending coronary artery (PDA), RCA, obtusemarginal branch, circumflex coronary artery, diagonal branch, and LAD.More generally, surgeons will revascularize the three coronary systemsin the following order: right, circumflex, and anterior descending.However, the order may vary depending on whether the procedure isperformed on a beating heart or an arrested heart. For arrested heart,about 3 to 4 bypass grafts of which 1 to 3 are free grafts are generallyperformed per procedure. In contrast, about 2 to 3 bypass grafts ofwhich 0 to 2 are free grafts are generally performed per beating heartprocedure. In general, 1 free graft is used per beating heart procedure.

When a saphenous vein or other blood vessel is used as a free graft in aprocedure, two anastomoses are performed; one to the diseased arterydistal to the obstruction (outflow end), and one proximally to the bloodvessel supplying the arterial blood (inflow end). These anastomoses aregenerally performed using end-to-side anastomotic techniques. Rarely anend-to-end anastomotic technique is used. When more than one graft isrequired in any of the three coronary systems for completerevascularization of the heart, sequential graft techniques may be usedto conserve the amount of blood vessels required. Sequential grafttechniques use proximal side-to-side anastomoses and an end-to-sideanastomosis to complete the graft. For example, a common sequence usedin the anterior descending coronary system is a side-to-side anastomosisof graft to the diagonal branch and an end-to-side anastomosis of graftto the LAD coronary artery. However, only a small percentage ofanastomoses are side-to-side anastomoses.

The majority of surgeons will complete the distal anastomosis of a graftprior to completion of the proximal anastomosis. The small percentage ofsurgeons who do complete the proximal anastomosis first usually do so toallow antegrade perfusion of cardioplegic solution through the graftduring revascularization. Construction of the distal anastomosis, e.g.,a saphenous vein-coronary artery anastomosis, begins by first locatingthe target artery on the heart. Next, an incision is made through theepicardium and the myocardium to expose the artery. An arteriotomy isthen made using a knife to incise the artery. The incision is thenextended with a scissors. The length of the incision approximates thediameter of the saphenous vein, about 4 to 5 mm. The diameter of thetarget artery is generally 1.5 to 2.0 mm. Since, most surgeons currentlyfeel the distal take-off angle should be 30 to 45 degrees, the distalend of the saphenous vein is usually beveled at about 30 to 45 degrees.

Currently, surgeons generally construct the anastomosis via a ten-stitchrunning suture using 7-0 polypropylene suture material. The ten-stitchanastomosis typically comprises five stitches around the heel of thegraft and five stitches around the toe. The five stitches around theheel of the graft comprise two stitches to one side of the apex of thegraft and the artery, a stitch through the apex and two stitches placedat the opposite side of the apex. The graft is generally held apart fromthe coronary artery while the stitches are constructed using a needlemanipulated by a forceps. Suture loops are drawn up and the suturepulled straight through to eliminate purse-string effect. The fivestitches around the toe of the graft also comprises two stitches to oneside of the apex of the graft and the artery, a stitch through the apexand two stitches placed at the opposite side of the apex. Again, sutureloops are drawn up and the suture pulled straight through to eliminatepurse-string effect. The suture ends are then tied.

The proximal anastomosis of a saphenous vein graft to the aorta, i.e.,an aortosaphenous vein anastomosis, is formed by first removing thepericardial layer that covers the aorta. An occluding or side-bitingclamp may be placed on the aorta at the anastomosis site or an aortotomyocclusion device may be used following creation of the aortotomy. Asmall circular or elliptical portion of the ascending aorta is excisedforming a small opening 4 to 5 mm in diameter, i.e. the aortotomy. Anaortic punch typically facilitates this procedure. The opening for aright-sided graft is made anterior or to the right lateral side of theaorta, whereas an opening for a left-sided graft is made to the leftlateral side of the aorta. If the graft is to supply blood to the rightcoronary artery, the opening is generally made proximal on the aorta. Ifthe graft is to supply blood to the anterior descending coronary artery,the opening is generally made in the middle on the aorta. And, if thegraft is to supply blood to the circumflex artery, the opening isgenerally made distal on the aorta. The right graft opening is placedslightly in the right of the anterior midpoint of the aorta and the leftgraft opening slightly to the left. The end of the saphenous vein is cutback longitudinally for a distance of approximately 1 cm. A vascularclamp is placed across the tip of the saphenous vein to flatten it,thereby exposing the apex of the vein. Five suture loops of a runningsuture using 5-0 polypropylene are then placed around the ‘heel’ of thegraft and passed through the aortic wall. Two stitches are placed on oneside of the apex, the third stitch is placed precisely through the apexof the incision in the saphenous vein, and the final two stitches areplaced on the opposite side of the apex. Suture traction is used to helpexpose the edge of the aortic opening to ensure accurate needleplacement. Stitches include about 3 to 5 mm of the aortic wall foradequate strength. Suture loops are then pulled up to approximate thevein graft to the aorta. The remaining stitches are placed in acartwheel fashion around the aortic opening thereby completing theremainder of the anastomosis.

Left-sided grafts are oriented so the apex of the incision in the “heel”of the saphenous vein will face directly to the left side. The stitchesare placed in a clockwise fashion around the heel of the graft and in acounterclockwise fashion around the aortic opening. Right-sided graftsare oriented in a caudal fashion. The stitches are placed in acounterclockwise fashion around the heel of the graft and in a clockwisefashion around the aortic opening. Five suture loops complete the heelportion of the graft and an additional five or six are necessary tocomplete the toe of the graft. Finished proximal anastomoses typicallyhave a “cobra-head” appearance.

It is essential for the surgeon to take steps to minimize thepossibility of thrombosis, narrowing and/or premature closure of theanastomosis due to technical errors. Some surgeons feel the proximalanastomosis must have a take-off angle of 45 degrees while othersurgeons believe the take-off angle is not critical. In addition, it wasfelt that intima-to-intima contact of the vessels at the anastomosis wascritical for endothelization to occur, thereby making an ideal union ofthe vessels. However, most surgeons now feel intima-to-adventitiacontact is acceptable. The main objective of the surgeon is to create ananastomosis with an expected long-term patency rate of greater than 5 to10 years. The creation of an anastomosis currently takes approximately10-15 minutes.

One essential requirement for creating an anastomosis without error isadequate exposure of the target vessel. Acute visualization of thevessel walls is mandatory in order to properly place each stitch andavoid inadvertently including the back wall of the vessel in a stitch,which in effect narrows or completely occludes the vessel. In order toachieve the required exposure most surgeons will employee blood-lessfield devices such as shunts, snares, and misted blowers. Further,largely invasive surgical techniques are also employed to help thesurgeon gain access to the grafting site. For this reason, CABG surgeryis typically performed through a median sternotomy, which providesaccess to the heart and to all major coronary branches. A mediansternotomy incision begins just below the sternal notch and extendsslightly below the xiphoid process. A sternal retractor is used tospread the left and right rib cage apart for optimal exposure of theheart. Hemostasis of the sternal edges is typically obtained usingelectrocautery with a ball-tip electrode and a thin layer of bone wax.The pericardial sac is opened thereby achieving direct access to theheart.

A blood vessel or vessels for use in the graft procedure are mobilizedfrom the patient. This usually entails mobilizing either a mammaryartery or a saphenous vein, although other graft vessels as discussedabove may also be used. A heart-lung or cardiopulmonary bypass isperformed. This usually entails arterial and venous cannulation,connecting the bloodstream to a heart-lung machine, cooling the body toabout 32 degrees Celsius, cross clamping of the aorta and cardioplegicperfusion of the coronary arteries to arrest and cool the heart to about4 degrees Celsius. A proximal anastomosis may be performed on partialbypass using a partial occluding aortic cross-clamp or side-clamp. Thearrest or stoppage of the heart is generally required because theconstant pumping motion of the beating heart would make surgery upon theheart difficult in some locations and extremely difficult if notimpossible in other locations

Once cardiac arrest is achieved, then a graft (or grafts) is attached tothe relevant portions of a coronary artery (or arteries) followed byweaning from the cardiopulmonary bypass, restarting the heart anddecannulation. Finally the chest is closed.

Problems that may be associated with conventional CABG procedures withCPB include the initiation of a systemic inflammatory response due tothe interactions of blood elements with the artificial material surfacesof the CPB circuit. Global (hypothermic) cardiac arrest may result inglobal myocardial ischemia and cross clamping the ascending aorta maycontribute to the patient experiencing a post-operative stroke. In fact,recent studies have shown aortic clamping and manipulation may releaseatherosclerotic debris into the bloodstream, resulting in neurologicinjury.

Currently, the golden standard for creation of a vascular anastomosis ismanual suturing. Manual suturing may be used to attach vascular grafts(either autografts or prosthetic grafts) for coronary bypass,femoral-femoral bypass (to relieve inadequate circulation in the legs),and AV fistulas and/or shunts (access portals for repeated punctureapplications such as kidney dialysis or diabetes). However, a number ofcardiac surgical procedures, e.g., off-pump, beating heart CABGprocedures, minimally invasive procedures and even totally endoscopicprocedures with access through ports only, may require a variety of newanastomotic techniques. The ability of performing anastomoses withlimited or no CPB support may increase the possibility of performingmore CABG procedures using minimally invasive surgical techniques.Avoiding the use of cross clamps and CPB or dramatically reducing pumprun and cross clamp times may effectively minimize post-operativecomplications. For this reason, there is an increasing need for easier,quicker, less damaging, but reliable automated, semi-automated, or atleast facilitated methods to replace or enhance the normal process of amanually sutured vascular anastomosis.

The major objective of any CABG procedure is to perform a technicallyperfect anastomosis. However, creation of a technically perfectanastomosis is generally complex, tedious, time consuming and itssuccess is highly dependent on a surgeon's skill level. Therefore,creation of vascular anastomoses without the need to perform delicateand intricate suture lines may enable surgeons to more quickly createsimpler and effective anastomoses. Currently, there are a number oftechniques or procedures being investigated for facilitating the processof forming an anastomosis including vascular clips or staplers, glues,adhesives or sealants, laser welding, mechanical couplers, stents androbot-assisted suturing. These techniques are being developed forperforming end-to-end, end-to-side and/or side-to-side anastomoses withor without temporary blood flow interruption. In general, thesetechniques may include the use of various biomaterials and/orbiocompatible agents.

In an effort to reduce or eliminate occlusive anastomosis time, varioustechniques or procedures are being investigated. These proceduresinclude coronary shunting techniques, which enable manual suturingwithout time-constraint due to persistent distal perfusion, andaccelerated tissue-bonding techniques, e.g., tissue adhesives and laserwelding. Some nonocclusive anastomosis techniques being developedrequire apposition of the intima of the graft to the adventitia of therecipient artery.

Sealants, adhesives or glues may be based on synthetic or biologicalsubstances or a combination of both. They are generally used to eitherseal post-operative internal air or fluid leaks, or to close a topicalwound. Surgical sealants are generally absorbable materials usedprimarily to control internal bleeding and to seal tissue. Surgicaladhesives, stronger than sealants, are often non-absorbable, but tend tobe biologically based. Surgical glues, stronger than adhesives, areoften synthetic and non-absorbable. In addition, glues are often usedfor topical wounds. Surgical glues are typically made fromcyanoacrylates, a strong adhesive found in commercially available superglues. Biologically based sealants, adhesives or glues are generallyderived from blood clotting components such as proteins (e.g.,fibrinogen or fibrin), enzymes (e.g., thrombin) and/or platelets. Fibrinbased sealants, adhesives or glues generally combine the proteinfibrinogen with the enzyme thrombin to immediately begin the clottingprocess. One surgical adhesive currently being marketed includes acombination of collagen (proteins which form fibers to support bodytissues), formalin (a form of formaldehyde), resorcinol andglutaraldehyde. Some sealants, adhesives or glues may be used to controlbleeding or to reinforce suture or staple lines rather than to maketissues adhere, thus functioning more as hemostatic agents than glues.

There are a number of uses for sealants, adhesives or glues such asreplacement for sutures and staples in minimally invasive procedureswhere the surgeon has little room to maneuver or for the repair ofaortic dissections, where the tissue is so thin it may be damaged bysutures. They may also be used for anastomotic sealing, in which theseal should not be absorbed or carotid patching, where a complete sealis desired.

Laser welding is another potential method for forming an anastomosis.Laser welding uses lasers such as CO₂ lasers, argon lasers orNeodymium-YAG lasers, to join tissues together thermally instead of, forexample, mechanically. One possible mechanism of laser welding oftissues is the thermal denaturation and coagulation of collagen fibrilsin the tissue, which generally occur above 60° C. To improve theprocedure, photosensitive dyes (e.g., indocyanine green) may be appliedat the weld site to enhance light absorption and minimize thermal damageto the surrounding tissue. Using a dye that adsorbs light at a veryspecific frequency, a laser can be then used to selectively heat the dyeand not the surrounding tissue. Photosensitive dyes used in laserwelding procedures may or may not bind chemically to the tissue'sproteins. Unlike sutures or staples, laser welding may offer a watertight seal to hold bodily fluids in, thereby preventing blood loss,infections and repeat surgeries. A further enhancement to the laserwelding technique is to use a “solder”. Solders may comprise syntheticand/or biological components. For example, proteins such as albumin havebeen used in various solder formulations. Typical laser welding devicesinclude one or more flexible optical fibers and solder-delivery tubesthat may be snaked through small ports or through a channel in anendoscope.

Mechanical anastomotic devices include stapling devices, clippingdevices, ring and pin coupling devices and suturing devices. Theseanastomotic devices may be automated or semi-automated. Mechanicalanastomotic devices also include mechanical couplers including stents,ferrules, and/or rings. Materials used to form an anastomosis via amechanical device and/or coupler may be biocompatible, bioabsorbable,bioactive and/or bioinert.

One component intra-luminal mechanical anastomotic devices are generallystent-like in design. The graft and the target vessel, i.e., the aortaor coronary artery, are forced into tubular shapes by the device. Ingeneral, the application of this type of device is relatively easy. Thedevice can be made to unfold by itself so no deformation forces arenecessary at the anastomosis. In addition, angled anastomoses arepossible. The device may however have a lot of foreign material exposedwithin the blood stream, thus increasing the risk of stenosis andthrombosis. In some cases, the device may prevent direct contact betweenthe graft and the target vessel, thereby preventing the vessel wallsfrom healing together. Intimal damage to both the graft and the targetvessel may also occur during delivery of the device. Extra sealingmethods, e.g., tissue sealants, may be necessary to provide a leak-freeanastomosis. In addition, the size of the device is strongly related tothe size of the vessels. Therefore, a range of devices and measurementof the vessels is necessary.

Two component intra-luminal mechanical anastomotic devices require boththe graft and the target vessel to be connected to their own couplingcomponent, after which the two coupling components are connected to eachother, thereby forming the complete anastomosis. Problems associatedwith construction of an anastomosis using a two component intra-luminalmechanical coupling device include mounting of the vessels andconnection of the components. Tools for mounting the individual couplingcomponents to each vessel and tools for connecting the couplingcomponents together are both required.

One component extra-luminal mechanical anastomotic devices generallyrequire a delivery tool to position the coupling device in the recipientvessel. One component extra-luminal mechanical coupling devicesgenerally allow direct intima-to-intima contact. In addition, this typeof device will have less foreign material in the blood stream, therebydecreasing the risk of stenosis and thrombosis. For this reason, lessbiological testing may be required as opposed to an intra-luminalstent-like device. However, mounting of the graft to the coupling devicemay not be easy. Damage may occur due to everting of the graft onto thedevice. For example, everting of a graft onto a device may cause damageto the intimal layer. This damage may occur for two reasons: 1) solidgrabbing of the vessel wall is necessary to evert an artery, thus onetip of the pair of pincers will roughly touch the intima; and, 2)eversion causes high strain (stretching), which will damage thearteries. Another problem is that skills are still necessary for propereversion. The surgeon has to estimate where to grab the vessel wall andhow to lift it over one of the pins to obtain a symmetrical anastomosis.A specially designed mounting tool may make the step of mounting thegraft onto the coupling device easier and may help to minimize damage tothe graft. In addition, care must be taken to avoid compression oftissue by the coupling device since compression can cause pressurenecrosis.

Two component extra-luminal mechanical anastomotic devices, like the twocomponent intra-luminal mechanical coupling devices, require both thegraft and the target vessel to be connected to their own couplingcomponent, after which the two coupling components are connected to eachother, thereby forming the complete anastomosis. Problems associatedwith construction of an anastomosis using a two component extra-luminalmechanical coupling device also include mounting of the vessels andconnection of the components. Tools for mounting the individual couplingcomponents to each vessel and tools for connecting the couplingcomponents together may be required.

Hybrid anastomosis techniques combine one or more techniques, e.g.,sutures or clips with glues or laser welding. A specific example of ahybrid anastomotic technique is the use of an intraluminal stent likedevice combined with an extraluminal application of biological glue.

One area which may create difficulties for the patient and extra expenseand time for a stopped heart CABG procedure involves CPB. In a CPBprocedure all the patient's blood, which normally returns to the rightatrium, is diverted to a system which supplies oxygen to the blood andremoves carbon dioxide from the blood and returns the blood, atsufficient pressure, into the patient's aorta for further distributioninto the body. Generally such a system requires several separatecomponents, including an oxygenator, several pumps, a reservoir, a bloodtemperature control system, filters as well as flow, pressure andtemperature sensors.

Problems may develop during cardiopulmonary bypass due to the reactionblood has to non-endothelially lined surfaces, i.e. surfaces unlikethose of a blood vessel. In particular, exposure of blood to foreignsurfaces results in the activation of virtually all the humoral andcellular components of the inflammatory response, as well as some of theslower reacting specific immune responses. Other complications fromcardiopulmonary bypass include loss of red blood cells and platelets dueto shear stress damage. In addition, cardiopulmonary bypass requires theuse of an anticoagulant, such as heparin. This may, in turn, increasethe risk of hemorrhage. Finally cardiopulmonary bypass sometimesnecessitates giving additional blood to the patient. The additionalblood, if from a source other than the patient, may expose the patientto blood born diseases.

Due to the risks incurred during cardiopulmonary bypass, others haveattempted to perform a coronary artery bypass graft procedure withoutcardiac arrest and cardiopulmonary bypass. For example, Trapp andBisarya in “Placement of Coronary Artery Bypass Graft Without PumpOxygenator”, Annals Thorac. Surg. Vol. 19, No. 1, (January 1975) pgs.1-9, immobilized the area of the bypass graft by encircling sutures deepenough to incorporate enough muscle to suspend an area of the heart andprevent damage to the coronary artery. More recently Fanning et al. in“Reoperative Coronary Artery Bypass Grafting Without CardiopulmonaryBypass”, Annals Thorac. Surg. Vol. 55, (February 1993) pgs. 486-489 alsoreported immobilizing the area of the bypass graft with stabilizationsutures.

Suction stabilization systems, such as the Medtronic Octopus® TissueStabilizer and Accessories (available from Medtronic, Inc., Minneapolis,Minn. USA), the current model being designated the “Octopus 3™stabilization system”, use suction to grip and immobilize the surface ofthe heart. Additionally, the system allows the surgeon to manipulate theanastomosis site into better view by rotating and supporting the heart.See, also, e.g., U.S. Pat. Nos. 5,836,311; 5,927,284 and 6,015,378, andco-assigned U.S. patent applications Ser. No. 09/396,047, filed Sep. 15,1999, Ser. No. 09/559,785, filed Apr. 27, 2000, and Ser. No. 09/678,203,filed Oct. 2, 2000; and European Patent Publication No. EP 0 993 806.The Octopus™ stabilizer facilitates moving or repositioning the heart toachieve better access to areas which would otherwise be difficult toaccess, such as the posterior or backside of the heart.

It would be desirable to have an organ positioning system and methodthat comprises a device that engages organ tissue and allows a surgeonto easily position, manipulate, stabilize and/or hold an organ during amedical procedure.

It would further be desirable to have an organ positioning system andmethod that comprises a device that engages organ tissue and allows asurgeon to easily position, manipulate, stabilize and/or hold an organduring an ablation procedure.

It would be desirable to have an organ positioning system and methodthat comprises a device that engages organ tissue and allows a surgeonto easily position, manipulate, stabilize and/or hold an organ during ananastomotic procedure.

It would be desirable to have an organ positioning system and methodthat comprises a device that engages organ tissue and allows a surgeonto easily position, manipulate, stabilize and/or hold an organ during acontrolled intermittent asystole procedure.

It would further be desirable to have an organ positioning system andmethod that comprises a device that engages organ tissue and allows asurgeon to easily position, manipulate, stabilize and/or hold organtissue during a medical procedure, thereby providing adequate exposure,e.g., adequate visualization and/or access, to a surgical site.

It would further be desirable to have an organ positioning system andmethod that allows the organ, for example, heart to be positioned in adesired orientation but otherwise allowing movement of the heart as theheart beats.

It would further be desirable to have an organ positioning system andmethod that is designed to be relatively atraumatic to tissue.

It would further be desirable to have an organ positioning system andmethod which is capable of positioning, manipulating, stabilizing and/orholding an organ and/or tissue while controllably monitoring one or morechemical, physical or physiological characteristics of a bodily tissueor fluid during a medical procedure.

It would further be desirable to have an organ positioning system andmethod which is capable of positioning an organ and/or tissue whilecontrollably providing suction during a medical procedure.

It would further be desirable to have an organ positioning system andmethod which is capable of positioning, manipulating, stabilizing and/orholding an organ and/or tissue while controllably providing fluid duringa medical procedure.

It would further be desirable to have an organ positioning system and,method which is capable of positioning, manipulating, stabilizing and/orholding an organ and/or tissue while controllably providing energyduring a medical procedure.

It would further be desirable to have an organ positioning system andmethod which is capable of positioning, manipulating, stabilizing and/orholding an organ and/or tissue while controllably providing illuminationduring a medical procedure.

SUMMARY OF THE INVENTION

One aspect of the present invention provides a system for positioning,manipulating, holding, grasping, immobilizing and/or stabilizing anorgan, such as a heart. The system may include one or moretissue-engaging devices, one or more suction sources, one or more fluidsources, one or more energy sources, one or more sensors and one or moreprocessors. The system may also include an indifferent electrode, a drugdelivery device and/or an illumination device. A tissue-engaging deviceof the system may comprise a tissue-engaging head, a support apparatusand a clamping mechanism for attaching the tissue-engaging device to astable object, such as a retractor that is fixed to a patient's chest. Atissue-engaging device of the system may comprise one or more energytransfer elements connected to an energy source, one or more sensorsconnected to a processor, one or more suction openings connected to asuction source, and/or one or more fluid openings connected to a fluidsource.

Another aspect of the present invention provides a method ofpositioning, manipulating, holding, grasping, immobilizing and/orstabilizing an organ, such as a heart. The method includes engaging andpositioning an organ, such as a heart, during a medical procedure. Themedical procedure may include deployment of one or more anastomoticdevices, e.g., during a CABG procedure. The medical procedure mayinclude intermittently stimulating a vagal nerve and pacing a heart. Themedical procedure may include ablating one or more tissues of a heart.The medical procedure may include placement of a lead on or within aheart. The method may include the use of suction to engage and positionan organ, such as a heart.

The foregoing, and other, features and advantages of the invention willbecome further apparent from the following detailed description of thepresently preferred embodiments, read in conjunction with theaccompanying drawings. The detailed description and drawings are merelyillustrative of the invention rather than limiting, the scope of theinvention being defined by the appended claims in equivalence thereof.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic view of one embodiment of a system in accordancewith the present invention.

FIG. 2 is a side view of one embodiment of a medical device inaccordance with the present invention.

FIG. 3 is a top view of one embodiment of a tissue-engaging head of amedical device in accordance with the present invention.

FIG. 4 is a cross-sectional view of one embodiment of a tissue-engaginghead of a medical device in accordance with the present invention.

FIG. 5 is a bottom view of one embodiment of a tissue-engaging head of amedical device in accordance with the present invention.

FIG. 6 is a cross-sectional view of one embodiment of a tissue-engaginghead of a medical device in accordance with the present invention.

FIG. 7 is a cross-sectional view of one embodiment of a tissue-engaginghead of a medical device in accordance with the present invention.

FIG. 8 is a side view of one embodiment of a medical device inaccordance with the present invention.

FIG. 9 is a cross-sectional view of one embodiment of a tissue-engaginghead of a medical device in accordance with the present invention.

FIG. 10 is a bottom view of one embodiment of a tissue-engaging head ofa medical device in accordance with the present invention.

FIG. 11 is a bottom view of one embodiment of a tissue-engaging head ofa medical device in accordance with the present invention.

FIG. 12 is a bottom view of one embodiment of a tissue-engaging head ofa medical device in accordance with the present invention.

FIG. 13 is a side view of one embodiment of a tissue-engaging head of amedical device in accordance with the present invention.

FIG. 14 is a side view of one embodiment of a tissue-engaging head of amedical device in accordance with the present invention.

FIG. 15 is an illustration of one embodiment of a medical device in usein accordance with the present invention.

FIG. 16 is an illustration of one embodiment of a medical device in usein accordance with the present invention.

FIG. 17 is an illustration of one embodiment of a medical device in usein accordance with the present invention.

FIG. 18 is an illustration of one embodiment of a medical device in usein accordance with the present invention.

FIG. 19 is a side view of one embodiment of a tissue-engaging head of amedical device in accordance with the present invention.

FIG. 20 is a bottom view of one embodiment of a tissue-engaging head ofa medical device in accordance with the present invention.

FIG. 21 is a bottom view of one embodiment of a tissue-engaging head ofa medical device in accordance with the present invention.

FIG. 22 is a side view of one embodiment of a tissue-engaging head of amedical device in accordance with the present invention.

FIG. 23 is a bottom view of one embodiment of a tissue-engaging head ofa medical device in accordance with the present invention.

FIG. 24 is a side view of one embodiment of a tissue-engaging head of amedical device in accordance with the present invention.

FIG. 25 is a bottom view of one embodiment of a tissue-engaging head ofa medical device in accordance with the present invention.

FIG. 26 is an illustration of one embodiment of a medical device in usein accordance with the present invention.

FIG. 27 is an illustration of one embodiment of a medical device in usein accordance with the present invention.

FIG. 28 is an illustration of one embodiment of a system in accordancewith the present invention.

FIG. 29 is a flow diagram of one embodiment of the present invention.

FIG. 30 is a flow diagram of one embodiment of the present invention.

FIG. 31 is a flow diagram of one embodiment of the present invention.

FIG. 32 is an illustration of one embodiment of a medical device in usein accordance with the present invention.

FIG. 33 is an illustration of one embodiment of a medical device in usein accordance with the present invention.

FIG. 34 is a schematic view of one embodiment of a medical device withan illumination device.

DETAILED DESCRIPTION OF THE PRESENTLY PREFERRED EMBODIMENTS

FIG. 1 shows a schematic view of one embodiment of system 10 forpositioning, manipulating, holding, grasping, immobilizing and/orstabilizing tissue in accordance with the present invention. In thisembodiment, system 10 is shown to comprise tissue-engaging device 20, asuction source 30, a fluid source 40, an energy source 50, a sensor 60and a processor 70. System 10 may also include an indifferent electrode,a drug delivery device and/or an illumination device (all not shown inFIG. 1). The indifferent electrode may be placed on the patient's bodysuch as the back, thigh or shoulder or another site other than thesuction site. The drug delivery device may be used to deliver drugs to apatient. The illumination device may be used to illuminate a surgicalsite.

As shown in FIG. 2, in one embodiment of the present invention,tissue-engaging device 20 may comprise a tissue-engaging head 221, asupport apparatus 222 and a clamping mechanism 223 for attaching device20 to a stable structure, such as a retractor (not shown in FIG. 2),that is fixed to a patient. Tissue-engaging device 20 may also compriseone or more energy transfer elements, one or more connectors forconnecting the one or more energy transfer elements to energy source 50,one or more sensing elements, one or more connectors for connecting theone or more sensing elements to sensor 60, one or more suction openings,one or more conduits for providing suction from suction source 30 to theone or more suction openings, one or more fluid openings, one or moreconduits for providing fluid from fluid source 40 to the one or morefluid openings, and/or one or more connectors for connecting one or morecomponents of tissue-engaging device 20 to processor 70.

Tissue-engaging device 20 and its components are preferably made of oneor more biocompatible materials. Biocompatible materials or biomaterialsare usually designed and constructed to be placed in or onto tissue of apatient's body or to contact fluid of a patient's body. Ideally, abiomaterial will not induce undesirable reactions in the body such asblood clotting, tumor formation, allergic reaction, foreign bodyreaction (rejection) or inflammatory reaction; will have the physicalproperties such as strength, elasticity, permeability and flexibilityrequired to function for the intended purpose; may be purified,fabricated and sterilized easily; will substantially maintain itsphysical properties and function during the time that it remains incontact with tissues or fluids of the body.

Materials that are either biocompatible or may be modified to bebiocompatible and may be used to make suction device 20 may includemetals such as titanium, titanium alloys, TiNi alloys, shape memoryalloys, super elastic alloys, aluminum oxide, platinum, platinum alloys,stainless steels, stainless steel alloys, MP35N, elgiloy, haynes 25,stellite, pyrolytic carbon, silver carbon, glassy carbon, polymers orplastics such as polyamides, polycarbonates, polyethers, polyesters,polyolefins including polyethylenes or polypropylenes, polystyrenes,polyurethanes, polyvinylchlorides, polyvinylpyrrolidones, siliconeelastomers, fluoropolymers, polyacrylates, polyisoprenes,polytetrafluoroethylenes, rubber, dacron, minerals or ceramics such ashydroxapatite, epoxies, human or animal protein or tissue such as bone,skin, teeth, collagen, laminin, elastin or fibrin, organic materialssuch as wood, cellulose, or compressed carbon, and other materials suchas glass, and the like. Materials that are not considered biocompatiblemay be modified to become biocompatible by a number of methods wellknown in the art. For example, coating a material with a biocompatiblecoating may enhance the biocompatibility of that material.

One or more surfaces of tissue-engaging device 20 may be coated with oneor more radioactive materials and/or biological agents such as, forexample, an anticoagulant agent, an antithrombotic agent, a clottingagent, a platelet agent, an anti-inflammatory agent, an antibody, anantigen, an immunoglobulin, a defense agent, an enzyme, a hormone, agrowth factor, a neurotransmitter, a cytokine, a blood agent, aregulatory agent, a transport agent, a fibrous agent, a protein, apeptide, a proteoglycan, a toxin, an antibiotic agent, an antibacterialagent, an antimicrobial agent, a bacterial agent or component,hyaluronic acid, a polysaccharide, a carbohydrate, a fatty acid, acatalyst, a drug, a vitamin, a DNA segment, a RNA segment, a nucleicacid, a lectin, an antiviral agent, a viral agent or component, agenetic agent, a ligand and a dye (which acts as a biological ligand).Biological agents may be found in nature (naturally occurring) or may bechemically synthesized by a variety of methods well known in the art.

Tissue-engaging device 20 may comprise a tissue-engaging head. Thetissue-engaging head may be flexible thereby allowing the head toconform to the surface of target tissue. The tissue-engaging head may bemalleable thereby allowing a surgeon to shape the head to conform to thesurface of target tissue. The tissue-engaging head may be rigid having ashape conforming to the surface of target tissue. The tissue-engaginghead may comprise a tissue contact surface. The tissue contact surfaceof the tissue-engaging head may be shaped or is shapeable to conform tothe surface of the target tissue.

In one embodiment of the present invention, the tissue-engaging head ofdevice 20 is formed of medical grade silicone rubber or thermoplasticelastomeric material (e.g., polyurethane). Preferably, the materialselected in this embodiment has a low durometer (e.g., about 50) so thatthe tissue-engaging head may conform to the surface of the heart. Thematerial selected may be a substantially transparent or translucentmaterial. Further contemplated are embodiments in which thetissue-engaging head is made of multiple materials of differentdurometers and properties, to form, for example, an endoskeleton orexoskeleton to provide varying degrees of stiffness and flexibilityalong different portions of the tissue-engaging head.

The tissue-engaging head may comprise one or more suction or vacuumports, openings, orifices, channels or elements positioned on, along,within or adjacent a tissue contact surface. The suction ports,openings, orifices, channels or elements may communicate suction throughthe tissue contact surface to the atmosphere. A tissue-engaging suctionhead is designed to engage or grasp tissue via suction. Each suctionport, opening, orifice, channel or element may have a suction aperturecoupling the port, opening, orifice, channel or element to a suctionconduit, passageway or lumen. The suction aperture may be located in thecenter or at a position slightly off-center of the suction port,opening, orifice, channel or element. The suction aperture may be anyshape including circular, oval, rectangular, or triangular. Each suctionport, opening, orifice, channel or element may also be any suitableshape, for example circular, oval, rectangular, or triangular.

Preferably, each suction aperture would have a smaller diameter than thearea of each suction port, opening, orifice, channel or element. Asmaller diameter creates a high resistance pathway between the suctionport, opening, orifice, channel or element and the suction conduit.Because of the high resistance pathway, loss of a tissue-to-port seal inone suction port (and thus loss of fixation of the suction port to thetissue) should not cause a precipitous pressure drop in the remainder ofthe suction ports.

Suction ports, openings, orifices, channels and/or elements may bearranged in any suitable fashion, such as a row or circle. In addition,the specific number of ports and their position may vary.Tissue-engaging head of device 20 may be covered with a removablecovering during insertion into a patient's body to prevent blood ortissue from clogging the suction openings, although this is notnecessary. Such coverings may include coverings of biocompatiblematerial that would cover the entire tissue-engaging head of device 20.Alternatively, coverings may be placed just over the ports, such as, forexample, mesh coverings or ribbed coverings.

A flexible tissue-engaging head may help to seal the head against tissuethereby helping to maintain suction. A sufficiently flexible head maydraw down toward the surface of the heart more than the surface of theheart is pulled up into the tissue-engaging head.

In one embodiment of the present invention, the tissue-engaging head maycomprise one or more mechanical means for engaging and/or graspingtissue. For example, the tissue-engaging head may comprise one or morehooks, clamps, screws, barbs, sutures, straps, tethers and/or staples.The tissue-engaging head may comprise a cuff or basket-type devicedesigned to fit completely or partially around an organ, e.g., a heart.The tissue-engaging head may comprise one or more chemical means forengaging and/or grasping tissue. For example, the tissue-engaging headmay comprise tissue glue or adhesive. The tissue-engaging head maycomprise one or more coupling means for engaging and/or grasping tissue.For example, a suction means in addition to a mechanical means may beused to engage or grasp tissue. A magnetic means may also be used toengage or grasp tissue.

In one embodiment of the present invention, the tissue-engaging head221, as shown in FIG. 3, may comprise a plurality of legs that may flexto conform to the surface of the heart. The legs of the tissue-engaginghead may be arranged in starfish-shaped configuration. Preferably inthis embodiment, there are 2-4 legs and, most preferably, there are 3legs. The legs may be generally arcuate, curving downwardly away fromthe attached ends of the legs to the free ends of the legs. The legs maybe sufficiently flexible that they may bend to conform to flat or curvedsurfaces, facilitating use of the tissue-engaging head at the apex orelsewhere on the heart.

In use, the legs may allow the tissue-engaging head to be oriented toavoid placement over particular features of the heart anatomy, such asthe cardiac arteries, or to avoid conflict with other surgical devices,such as a heart stabilizer of the type sold under the trade designation“OCTOPUS” by Medtronic, Inc., Minneapolis, Minn., USA.

In one embodiment of the present invention, the tissue-engaging head ofdevice 20 may be sufficiently resiliently flexible that it may flex toallow it to be pushed through a small incision, cannula or port. Onceinside the chest cavity, the flexible head will return to its originalshape. For example, the legs may be configured and sufficiently flexiblethat they can be drawn against one another to a collapsed position forentering into a thoracic cavity through a small incision, cannula orport in endoscopic and/or closed chest surgery. In addition, to closedchest surgery, this invention is applicable to open chest/split sternumsurgery, in particular open chest, beating heart surgery forrepositioning the heart to improve access to various coronary arteries.

One or more suction ports, openings, orifices, channels and/or elements424 may be provided along a tissue contact surface or tissue-engagingface of suction head 221 in fluid communication with the legs to applysuction between the legs and the surface of the heart to grasp thesurface (see FIGS. 4 and 5). One or more suction ports, openings,orifices, channels and/or elements may be positioned in or on each leg.

As shown in FIGS. 4 and 5, one or more tissue-engaging members orstandoffs 425 may be provided within the tissue-engaging head to preventvacuum channels from being closed off as tissue and the suction head aredrawn together to allow continued fluid communication along the vacuumchannels. In addition, one or more tissue-engaging members may beprovided adjacent the orifice of a vacuum passageway to prevent theorifice and tissue being drawn together to close the orifice, therebymaintaining fluid communication between the vacuum passageway and thevacuum channels.

FIGS. 6 and 7 illustrate one embodiment of a tissue-engaging suctionhead 221 in which a resiliently flexible flange 426 (also shown in FIG.4) resiliently deforms against heart tissue 603 to form a seal to helpmaintain the vacuum in vacuum channel 424. The standoff ortissue-engaging member 425 limits how far suction head 221 may be pulleddown toward the surface of the heart to maintain vacuum channel 424, asillustrated in FIG. 7. tissue-engaging members may be elongated having adirection of elongation extending generally radially with respect to anorifice.

The end of each flange may be beveled as illustrated in FIG. 4 so thatthe laterally outward edge of each end extends further than thelaterally inward edge of each end. Flange 426 may extend alongsubstantially the entire periphery of suction head 221, see FIG. 5, sothat vacuum can be maintained in the area defined between flange 426,the body of suction head 221 and the surface of the heart.

Tissue-engaging head of device 20, may comprise one or more bumps 427,for example, located on the inner surface of resiliently flexibleperipheral flange 426, see FIG. 4. Most preferably, bumps 427 aregenerally hemispherical convex structures forming an integral part ofthe inner surface of the peripheral flange 426. When suction is pulledthrough vacuum channel 424, bumps 427 are pulled against the surface ofan organ as flange 426 deforms against the surface of the organ, e.g.,the epicardium of the heart. Bumps 427 help retain suction head 221 inplace on the heart. Bumps 427 may be arranged in an alternating pattern,aligned pattern or irregular pattern, for example.

Textures other than bumps are also contemplated, such as dimples,spikes, ridges, grooves (e.g., microgrooves), roughened texture (e.g.,micro-textured), surface grain, strips, ribs, channels, ruts, embeddingor adhering abrasive particles in or on the surface, gluing orlaminating the texture onto the surface, or other surface treatments,conditions or configurations that increase the grip of the inner surfaceof the tissue-engaging head on the epicardium. It is also contemplatedthat the other underside surfaces of the tissue-engaging head may betextured to increase surface area and/or gripping. For example, atexture is preferably provided on the tissue-engaging members orstandoffs 425, and this texture may be in the same form as the textureon the inner surface of the peripheral flange 426 or a differentgripping texture. The texture may be formed by any suitable methods,such as by molding, chemical etching, roughening with sandpaper or otherabrasives (e.g., sand blasting), electrical means (such as EDMmachining), thermal means, or laser etching, for example.

FIG. 2 illustrates one embodiment of the tissue-engaging head 221 inwhich tube fitting 224 includes a ninety degree bend. Other tubefittings having other angles of bend are also contemplated. The tubefitting 224 receives a vacuum line (not shown in FIG. 2).Tissue-engaging head 221 and tube fitting 224 may be free to rotaterelative to the end of support arm 222. FIG. 2 also illustrates yet oneembodiment of tissue-engaging head 221 in which a filter element 225 isprovided within the tube fitting 224. The filter element 225 preferablyincludes a through bore.

The tissue-engaging device 20 may include one or more fluid openings fordelivery and/or removal of one or more fluids. Tissue-engaging device 20may include needles for injection of fluids, drugs and/or cells intoorgan tissue. As shown in FIGS. 8, 9 and 10, tissue-engaging device 20may comprise catheter or cannula 810 for blood removal or delivery intoan organ, e.g., a heart. In the case of the heart, the cannula orcatheter may be placed through the wall of the heart and into aninterior chamber of the heart comprising blood, for example, into theleft ventricle. Blood may be removed or delivered via a blood pump. Forexample, tube fitting 811, which is in fluid communication with catheteror cannula 810, may be attached to a CPB circuit or a cardiac assistcircuit such as an LVAD circuit. Tissue-engaging device 20 may includeone or more openings for delivery or removal of one or more gasesincluding smoke evacuation.

As mentioned earlier and as shown in FIG. 11, one or moretissue-engaging members or standoffs 425 may be provided within thetissue-engaging head to prevent vacuum channels from being closed off astissue and the suction head are drawn together to allow continued fluidcommunication along the vacuum channels. Alternatively or in addition tostandoffs, a porous screen, mesh and/or fabric 450 (as shown in FIG. 12)may be used to prevent the orifice and tissue being drawn together toclose the orifice, thereby maintaining fluid communication between thevacuum passageway and the vacuum channels. The screen, mesh and/orfabric may engage or contact tissue. The screen, mesh and/or fabric maybe placed on top of standoffs. The screen, mesh and/or fabric maycomprise a number of materials including metallic, ceramic and/orpolymeric materials. The screen, mesh and/or fabric may be made of asynthetic or natural material. In one embodiment of the presentinvention, the mesh may be made of a medical grade Dacron material. Asshown in FIG. 13, the screen, mesh and/or fabric may comprise bumps 451.Alternatively or in addition to standoffs, a porous foam 452 (as shownin FIG. 14), e.g., a polymeric foam, or other porous material ormaterials may be used to prevent the orifice and tissue being drawntogether to close the orifice, thereby maintaining fluid communicationbetween the vacuum passageway and the vacuum channels.

The tissue-engaging head may be designed to be an implantable medicaldevice. For example, following a medical procedure such as a CABGprocedure the tissue-engaging head may be left within the patient,thereby providing benefit to the patient. The tissue-engaging head maybe made of one or more biodegradable materials, thereby allowing thehead to be absorbed by the patient over time.

Tissue-engaging device 20 may comprise a maneuvering or supportapparatus or means such as a shaft, a handle or an arm 222, as shown inFIGS. 2 and 8, connected to the tissue-engaging head to position thehead to thereby position or hold tissue such as the heart. The supportshaft, handle or arm may be rigid, flexible, telescoping orarticulating. The shaft, handle or arm may comprise one or more hingesor joints for maneuvering and placing device 20 against tissue. Thehinges or joints of the maneuvering or support apparatus may be actuatedremotely, for example with pull wires, from outside a patient's body.The shaft, handle or arm may be malleable or shapeable. The maneuveringor support means may be made of a shape memory alloy wherein heat may beuse to change the shape of the maneuvering or supporting means.

The support shaft, handle or arm may be of the type that can readily bechanged between a flexible or articulating condition and a rigidcondition. For example, a support arm may comprise a plurality of rigidmembers that are free to articulate relative to one another until acentral cable pulls the rigid members together to lock the support armin a rigid condition. The cable is controlled, for example, by a handlethat rotates to pull tension on the cable, thereby drawing the rigidmembers together to lock them into position. Each rigid member hasopposite ends, one of which is concave and the other of which is convex(e.g., hemispherical). The convex end of one rigid member fits into theconcave end of the adjacent rigid member, and allows the member toarticulate relative to the adjacent member if the central cable has notbeen tensioned to lock the rigid members together. Most preferably, therigid members are not of uniform cross section, with the rigid memberscloser to the distal end having a smaller cross section than the rigidmembers closer to the proximal end. A suitable articulating mechanismcould be similar to the type used in the “OCTOPUS 3”™ tissuestabilization system sold by Medtronic, Inc., Minneapolis, Minn. USA.See, also, the articulating arm mechanisms disclosed in U.S. Pat. Nos.5,836,311; 5,927,284 and 6,015,378, co-assigned U.S. patent applicationSer. No. 09/396,047, filed Sep. 15, 1999; and Ser. No. 09/678,203, filedOct. 2, 2000, and European Patent Publication No. EP 0 993 806.

The tissue-engaging head of suction device 20 may be rigidly,permanently, moveably, or removeably coupled, connected or mounted ontothe maneuvering or support apparatus or means. For example, the head maybe coupled via a hinge or joint to an articulating support arm. The headmay be coupled, for example, to the maneuvering or support apparatus viaone or more springs, hinges, joints and/or bellows. The tissue-engaginghead may be designed to be detachable or replaceable; for example, thehead may snap on and/or off the maneuvering or support apparatus.Magnets, glues, screws and/or bolts may also be used to attach thetissue-engaging head to the maneuvering or support apparatus. Alsocontemplated is use of sets of tissue-engaging heads of different sizesand/or shapes.

The mechanism connecting the tissue-engaging head to the support arm maypermit the head to rotate and/or pivot on one or more axes relative tothe support arm. For example, the tissue-engaging head may be permittedto rotate relative to the support arm along a first axis, and thetissue-engaging head may be allowed to pivot relative to the support armalong a second axis generally perpendicular to the first axis. Thetissue-engaging head may be allowed to pivot and/or rotate along one ormore axes even after the support arm is locked into a rigid condition.

The mechanism connecting the tissue-engaging head to the support arm maycomprise one or more resiliently-flexible suspension elements. Thetissue-engaging head and suspension element may be integrally molded ofthe same material. As used herein, “integral” or “integrally molded”refer to constructions in which one continuous piece is formed, ratherthan separate pieces that are connected together (e.g., mechanically orby welding or adhesive). The suspension element may comprise a bellowstype structure that resiliently flexes to allow the tissue-engaging headto move in response to beating of the heart. The suspension element maybe expandable to allow the tissue-engaging head to stretch or movetoward and away from the support arm in response to the beating heart.The suspension element may allow movement including rotational andtwisting motions in one or more directions.

In one embodiment of the present invention, the suspension elementcomprises a bellows 226 (as shown in FIGS. 2 and 3) that flexes as thesuspension element is stretched. As the bellows is stretched, theeffective spring rate of the suspension element increases. A suctionand/or fluid passageway, conduit or lumen may extend through thebellows-type suspension element 226 (as shown in FIG. 4). The bellowsmay provide the further advantage of keeping the one or morepassageways, conduits or lumens open through normal stretching of thebellows. In an alternate embodiment, the suspension element comprises atwo-stage or multi-stage bellows providing a varying spring rate betweenstages, as well as a high spring rate when the bellows is stretched out.

Tissue-engaging device 20 may be fixed in position relative to apatient. For example, the maneuvering or support apparatus of device 20may be designed to attach to or lock onto one or more stable objectssuch as an operating table, a retractor, an endoscopic port and/or asupport arm of another tissue-engaging apparatus. A retractor may be,for example, a sternal retractor or a rib retractor. An endoscopic portmay be, for example, a cannula, such as a trocar cannula placed in apatient's chest. A portion of a patient's skeletal system may also beconsidered a stable object. FIG. 15 shows tissue-engaging device 20locked onto a sternal retractor 150 fixed to a patient's chest. In FIG.15, tissue-engaging device 20 is shown supporting a patient's heartwhile it is engaged or attached to the apex of the patient's heart. Thepatient's heart may be beating or stopped. FIG. 16 shows anotherembodiment of the present invention wherein support arm 162 of a firsttissue-engaging device 160 is attached or coupled via clamp 167 tosupport arm 164 of a second tissue-engaging device 163. Clamp 167 may bedesigned to couple or attach onto a variety of stable objects includingthe support arms of various tissue-engaging devices. The secondtissue-engaging device 163 is shown in FIG. 16 clamped onto a retractor150 that is fixed to a patient's chest via clamp 165. Retractor 150 isshown in FIG. 16 to comprise suture holders 168. In FIG. 16, the firsttissue-engaging device 160 is shown supporting a patient's heart whilehead 161 of device 160 is engaged or attached to the apex of the heart;the second tissue-engaging device 163 is shown stabilizing orimmobilizing an area of the heart while head 166 of device 163 isengaged or attached to the surface of the heart. In this embodiment ofthe present invention, the patient's heart may be beating or stopped.

The maneuvering or support apparatus may comprise one or more lumens orconduits for communicating suction and/or delivering and/or removingfluids and/or gases to the tissue-engaging head. The one or moreconduits or lumens may be connected to at least one suction openingand/or fluid opening located on tissue-engaging device 20.

In one embodiment of the present invention, the maneuvering or supportapparatus may be a suture, strap or tether. For example, thetissue-engaging head of device 20 may be attached to one or moresutures, straps or tethers which may be affixed or attached to a stableobject such as a retractor. For example, FIG. 17 illustrates atissue-engaging device 170 comprising a suction head 221 and a vacuumtube 171, which provides vacuum to suction head 221 and provides atether or means for manipulating and holding suction head 221 toposition and orient the heart. FIG. 18 illustrates a tissue-engagingdevice 180 comprising a suction head 221, vacuum tube 171, and suture,line or strap 181 that provides a tether or means for manipulating andholding suction head 221 to position and orient the heart. The suture,line or strap may be retained in a suture guide, clamp or lock 168, forexample, on a sternal retractor (as shown in FIG. 16), although it isalso contemplated that it could be retained on a rib retractor, port,cannula or other device or mechanism, or mounted on the patient,operating table or other stable or stationary object.

The tissue-engaging head may comprise one or more energy transferelements positioned on, along, within or adjacent a tissue contactsurface. Energy transfer elements transfer energy to target tissue. Forexample, energy transfer elements may be conductive elements that maysupply RF energy, microwave energy or ultrasound energy to targettissue. Energy transfer elements may be, for example, laser elements forsupplying laser light to target tissue or they may be cryo elements. Twoor more energy transfer elements or conductive elements oftissue-engaging device 20 may be arranged in a biopolar arrangementwherein at least one element is used as a positive electrode and atleast one element is used as a negative electrode. One or more energytransfer elements or conductive elements of tissue-engaging device 20may be arranged in a monopolar arrangement wherein at least one elementis used as one electrode and an indifferent electrode is placedelsewhere on the patient's body such as the back, thigh or shoulder oranother site other than the tissue-engaging device 20 site.

As shown in FIGS. 19 and 20, tissue-engaging head 221 may comprise oneor more energy transfer elements or electrodes 190. Electrodes 190 maybe connected to energy source 50 (not shown in FIGS. 19 and 20) viaelectrically conductive wires or leads 191. One or more electrodes 190may be positioned on one or more standoffs 425. For example, FIG. 20shows two electrodes 190 each positioned on a different standoff 425.FIG. 21 shows six electrodes 190 positioned in pairs on three differentstandoffs 425. In another embodiment of the present invention,tissue-engaging head 221 may comprise lead 191 coupled to a perimeterelectrode 190 positioned on or along flange 426 as demonstrated in FIGS.22 and 23. In another embodiment of the present invention,tissue-engaging head 221 may comprise lead 191 coupled to a conductivescreen or mesh electrode 190 as shown in FIGS. 24 and 25. For example,the conductive screen or mesh may be made of a metallic material or aconductive polymeric material or combinations thereof. In addition,electrode 190 may or may not be positioned on standoffs.

Energy transfer elements or conductive elements may comprise one or moreconductive materials or blends including titanium, titanium alloys, TiNialloys, shape memory alloys, super elastic alloys, aluminum oxide,platinum, platinum alloys, stainless steels, stainless steel alloys,MP35N, elgiloy, haynes 25, stellite, pyrolytic carbon, silver carbon,conductive metals, conductive polymers or plastics, and/or conductiveceramics. Energy transfer elements or conductive elements may not beconductive but may serve as a conduit to deliver a conductive materialsuch as a conductive fluid. Energy transfer elements or conductiveelements may be porous. For example, energy transfer elements orconductive elements may comprise porous polymers, metals, or ceramics.Energy transfer elements or conductive elements may be coated withnon-stick coatings such as PTFE or other types of coatings as discussedherein. Energy transfer elements or conductive elements may be flexiblethereby allowing them to conform to the surface of target tissue. Energytransfer elements or conductive elements may be malleable therebyallowing a surgeon to shape them to conform to the surface of targettissue.

Energy transfer elements or conductive elements may comprise one or moremetal conductors such as windings inside a polymer or a conductive meshmaterial. The energy transfer elements or conductive elements maycomprise tubes for delivering fluids. The tubes may comprise holes orslots. A polymer tube may be placed inside a metal tube to control fluiddeliver through energy transfer elements or conductive elements. One ormore of the energy transfer elements or conductive elements may be usedas one or more nerve stimulation electrodes and/or as one or morecardiac stimulation electrodes. Electrodes may be used for cardiacpacing, defibrillation, cardioversion, sensing, stimulation, and/ormapping.

Energy transfer elements or conductive elements may comprise needlesdesigned to penetrate tissues such as fat and muscle. For example,energy transfer elements or conductive elements may be designed topenetrate fat on the heart thereby allowing the energy transfer elementsor conductive elements to reach cardiac tissue. The needles may allowfluids such as conductive fluids, chemicals such as tissue ablationchemicals, drugs, biological agents and/or cells to pass through. Theneedles may allow a vacuum or suction to pass through.

Tissue-engaging device 20 may comprise one or more switches, e.g., asurgeon-controlled switch. One or more switches may be incorporated inor on tissue-engaging device 20 or any other location easily and quicklyaccessed by the surgeon for regulation of tissue-engaging device 20 bythe surgeon. A switch may be, for example, a hand switch, a foot switch,or a voice-activated switch comprising voice-recognition technologies. Aswitch may be physically wired to device 20 or it may be a remotecontrol switch.

Tissue-engaging device 20 may be slaved to suction source 30, fluidsource 40, energy source 50, sensor 60 and/or processor 70. For example,tissue-engaging device 20 may be designed to automatically stop engagingtissue when processor 70 sends a signal to stop tissue engagement.Tissue-engaging device 20 may include a visual and/or audible signalused to alert a surgeon to any change in tissue engagement and/or avisual and/or audible signal may be included in system 10. For example,a beeping tone or flashing light may be used to alert the surgeon whentissue-engaging device 20 has engaged tissue. Tissue-engaging device 20may be slaved to a robotic system or a robotic system may be slaved totissue-engaging device 20.

Tissue-engaging device 20 may be positioned and used, for example,through a thoracotomy, through a sternotomy, percutaneously,transvenously, arthroscopically, endoscopically, for example, through apercutaneous port, through a stab wound or puncture, through a smallincision, for example, in the chest, in the groin, in the abdomen, inthe neck or in the knee, or in combinations thereof. Tissue-engagingdevice 20 may be guided into a desired position using various guidancetechniques, e.g., flouroscopic guidance techniques.

System 10 may include suction source 30 for providing suction totissue-engaging device 20. As shown in FIG. 26, tissue-engaging device20 may be attached to a flexible or rigid hose or tubing 900 forsupplying suction and/or fluids from a suitable suction source and/orfluid source to the target tissue surface through suction and/or fluidelements, openings, orifices, or ports of device 20. Tubing 900 maycomprise one or more stopcocks 901 and/or connectors 902 such as luerconnectors. Suction may be provided to device 20 by the standard suctionavailable in the operating room. Suction source 30 may be coupled totissue-engaging device 20 with a buffer flask 903 and/or filter 904 asshown in FIG. 27. Suction may be provided at a negative pressure ofbetween 200-600 mm Hg with 400 mm Hg preferred. As used herein, theterms “vacuum” or “suction” refer to negative pressure relative toatmospheric or environmental air pressure in the operating room.

Alternatively, suction may be provided via one or more manual orelectric pumps, syringes, suction or squeeze bulbs or other suction orvacuum producing means, devices or systems. Suction source 30 and/ortubing 900 may comprise one or more vacuum regulators, resistors,stopcocks, connectors, valves, e.g., vacuum releasing valves, filters,conduits, lines, tubes and/or hoses. The conduits, lines, tubes, orhoses may be flexible or rigid. For example, a flexible suction line maybe used to communicate suction to device 20, thereby allowing device 20to be easily manipulated by a surgeon. Another method that would allowthe surgeon to easily manipulate device 20 includes incorporation ofsuction source 30 into device 20. For example, a small battery operatedvacuum pump or squeeze bulb may be incorporated into device 20.

Suction source 30 may be slaved to tissue-engaging device 20, fluidsource 40, energy source 50, sensor 60 and/or processor 70. For example,suction source 30 may be designed to automatically stop suction whenprocessor 70 sends a signal to stop suction. Suction source 30 mayinclude a visual and/or audible signal used to alert a surgeon to anychange in suction. For example, a beeping tone or flashing light may beused to alert the surgeon when suction is present. Suction source 30 maybe slaved to a robotic system or a robotic system may be slaved tosuction source 30. Suction may be used to secure, anchor or fixtissue-engaging device 20 to an area of tissue. The area of tissue maycomprise a beating heart or a stopped heart. Suction may be used toremove or aspirate fluids from the target tissue site. Fluids removedmay include, for example, blood, saline, Ringer's solution, ionicfluids, contrast fluids, irrigating fluids and energy-conducting fluids.Steam, vapor, smoke, gases and chemicals may also be removed viasuction.

System 10 may include fluid source 40 for providing fluids totissue-engaging device 20. Tissue-engaging device 20 may be attached toa flexible or rigid hose or tubing for supplying fluids from fluidsource 40 to the target tissue through fluid elements, openings,orifices, or ports of device 20. Fluid source 40 may be any suitablesource of fluid. Fluid source 40 may include a manual or electric pump,an infusion pump, a peristaltic pump, a roller pump, a centrifugal pump,a syringe pump, a syringe, or squeeze bulb or other fluid moving means,device or system. For example, a pump may be connected to a shared powersource or it may have its own source of power. Fluid source 40 may bepowered by AC current, DC current, or it may be battery powered eitherby a disposable or re-chargeable battery. Fluid source 40 may compriseone or more fluid regulators, e.g., to control flow rate, valves, fluidreservoirs, resistors, filters, conduits, lines, tubes and/or hoses. Theconduits, lines, tubes, or hoses may be flexible or rigid. For example,a flexible line may be connected to device 20 to deliver fluid and/orremove fluid, thereby allowing device 20 to be easily manipulated by asurgeon. Fluid reservoirs may include an IV bag or bottle, for example.

Fluid source 40 may be incorporated into tissue-engaging device 20,thereby delivering fluid or removing fluid at the target tissue site.Fluid source 40 may be slaved to tissue-engaging device 20, suctionsource 30, energy source 50, sensor 60 and/or processor 70. For example,fluid source 40 may be designed to automatically stop or start thedelivery of fluid while tissue-engaging device 20 is engaged withtissue. Fluid source 40 may be slaved to a robotic system or a roboticsystem may be slaved to fluid source 40.

Fluid source 40 may comprise one or more switches, e.g., asurgeon-controlled switch. One or more switches may be incorporated inor on fluid source 40 or any other location easily and quickly accessedby the surgeon for regulation of fluid delivery by the surgeon. A switchmay be, for example, a hand switch, a foot switch, or a voice-activatedswitch comprising voice-recognition technologies. A switch may bephysically wired to fluid source 40 or it may be a remote controlswitch. Fluid source 40 and/or system 10 may include a visual and/oraudible signal used to alert a surgeon to any change in the delivery offluid. For example, a beeping tone or flashing light may be used toalert the surgeon that a change has occurred in the delivery of fluid.

Fluids delivered to tissue-engaging device 20 may include saline, e.g.,normal, hypotonic or hypertonic saline, Ringer's solution, ionic,contrast, blood, and/or energy-conducting liquids. An ionic fluid mayelectrically tissue-engaging device 20 to tissue thereby lowering theimpedance at the target tissue site. An ionic irrigating fluid maycreate a larger effective electrode surface. An irrigating fluid maycool the surface of tissue thereby preventing over heating or cooking oftissue which can cause popping, desiccation, and charring of tissue. Ahypotonic irrigating fluid may be used to electrically insulate a regionof tissue. Fluids delivered to tissue-engaging device 20 may includegases, adhesive agents and/or release agents.

Diagnostic or therapeutic agents, such as one or more radioactivematerials and/or biological agents such as, for example, ananticoagulant agent, an antithrombotic agent, a clotting agent, aplatelet agent, an anti-inflammatory agent, an antibody, an antigen, animmunoglobulin, a defense agent, an enzyme, a hormone, a growth factor,a neurotransmitter, a cytokine, a blood agent, a regulatory agent, atransport agent, a fibrous agent, a protein, a peptide, a proteoglycan,a toxin, an antibiotic agent, an antibacterial agent, an antimicrobialagent, a bacterial agent or component, hyaluronic acid, apolysaccharide, a carbohydrate, a fatty acid, a catalyst, a drug, avitamin, a DNA segment, a RNA segment, a nucleic acid, a lectin, anantiviral agent, a viral agent or component, a genetic agent, a ligandand a dye (which acts as a biological ligand) may be delivered with afluid. Biological agents may be found in nature (naturally occurring) ormay be chemically synthesized. Cells and cell components, e.g.,mammalian and/or bacterial cells, may be delivered with a fluid.

One or more of a variety of pharmacological agents, biological agentsand/or drugs may be delivered or administered to a patient, for avariety of functions and purposes as described below, prior to a medicalprocedure, intermittently during a medical procedure, continuouslyduring a medical procedure and/or following a medical procedure. Forexample, one or more of a variety of pharmacological agents, biologicalagents and/or drugs, as discussed above and below, may be deliveredbefore, with or after the delivery of a fluid.

Drugs, drug formulations or compositions suitable for administration toa patient may include a pharmaceutically acceptable carrier or solutionin an appropriate dosage. There are a number of pharmaceuticallyacceptable carriers that may be used for delivery of various drugs, forexample, via direct injection, oral delivery, suppository delivery,transdermal delivery, epicardial delivery and/or inhalation delivery.Pharmaceutically acceptable carriers include a number of solutions,preferably sterile, for example, water, saline, Ringer's solution and/orsugar solutions such as dextrose in water or saline. Other possiblecarriers that may be used include sodium citrate, citric acid, aminoacids, lactate, mannitol, maltose, glycerol, sucrose, ammonium chloride,sodium chloride, potassium chloride, calcium chloride, sodium lactate,and/or sodium bicarbonate. Carrier solutions may or may not be buffered.

Drug formulations or compositions may include antioxidants orpreservatives such as ascorbic acid. They may also be in apharmaceutically acceptable form for parenteral administration, forexample to the cardiovascular system, or directly to the heart, such asintracoronary infusion or injection. Drug formulations or compositionsmay comprise agents that provide a synergistic effect when administeredtogether. A synergistic effect between two or more drugs or agents mayreduce the amount that normally is required for therapeutic delivery ofan individual drug or agent. Two or more drugs may be administered, forexample, sequentially or simultaneously. Drugs may be administered viaone or more bolus injections and/or infusions or combinations thereof.The injections and/or infusions may be continuous or intermittent. Drugsmay be administered, for example, systemically or locally, for example,to the heart, to a coronary artery and/or vein, to a pulmonary arteryand/or vein, to the right atrium and/or ventricle, to the left atriumand/or ventricle, to the aorta, to the AV node, to the SA node, to anerve and/or to the coronary sinus. Drugs may be administered ordelivered via intravenous, intracoronary and/or intraventricularadministration in a suitable carrier. Examples of arteries that may beused to deliver drugs to the AV node include the AV node artery, theright coronary artery, the right descending coronary artery, the leftcoronary artery, the left anterior descending coronary artery andKugel's artery. Drugs may be delivered systemically, for example, viaoral, transdermal, intranasal, suppository or inhalation methods. Drugsalso may be delivered via a pill, a spray, a cream, an ointment or amedicament formulation.

In one embodiment of the present invention, system 10 may include a drugdelivery device (not shown). The drug delivery device may comprise acatheter, such as a drug delivery catheter or a guide catheter, a patch,such as a transepicardial patch that slowly releases drugs directly intothe myocardium, a cannula, a pump and/or a hypodermic needle and syringeassembly. A drug delivery catheter may include an expandable member,e.g., a low-pressure balloon, and a shaft having a distal portion,wherein the expandable member is disposed along the distal portion. Acatheter for drug delivery may comprise one or more lumens and may bedelivered endovascularly via insertion into a blood vessel, e.g., anartery such as a femoral, radial, subclavian or coronary artery. Thecatheter can be guided into a desired position using various guidancetechniques, e.g., flouroscopic guidance and/or a guiding catheter orguide wire techniques. Drugs may be delivered via an iontophoretic drugdelivery device placed on the heart. In general, the delivery of ionizeddrugs may be enhanced via a small current applied across two electrodes.Positive ions may be introduced into the tissues from the positive pole,or negative ions from the negative pole. The use of iontophoresis maymarkedly facilitate the transport of certain ionized drug molecules. Forexample, lidocaine hydrochloride may be applied to the heart via a drugpatch comprising the drug. A positive electrode could be placed over thepatch and current passed. The negative electrode would contact the heartor other body part at some desired distance point to complete thecircuit. One or more of the iontophoresis electrodes may also be used asnerve stimulation electrodes or as cardiac stimulation electrodes.

A drug delivery device may be incorporated into tissue-engaging device20, thereby delivering drugs at or adjacent the target tissue site orthe drug delivery device may be placed or used at a location differingfrom the location of tissue-engaging device 20. For example, a drugdelivery device may be placed in contact with the inside surface of apatient's heart while tissue-engaging device 20 is placed or used on theoutside surface of the patient's heart.

The drug delivery device may be slaved to tissue-engaging device 20,suction source 30, fluid source 40, energy source 50, sensor 60 and/orprocessor 70. For example, a drug delivery device may be designed toautomatically stop or start the delivery of drugs during tissueengagement of tissue-engaging device 20. The drug delivery device may beslaved to a robotic system or a robotic system may be slaved to the drugdelivery device.

The drug delivery device may comprise one or more switches, e.g., asurgeon-controlled switch. One or more switches may be incorporated inor on the drug delivery device or any other location easily and quicklyaccessed by the surgeon for regulation of drug delivery by the surgeon.A switch may be, for example, a hand switch, a foot switch, or avoice-activated switch comprising voice-recognition technologies. Aswitch may be physically wired to the drug delivery device or it may bea remote control switch. The drug delivery device and/or system 10 mayinclude a visual and/or audible signal used to alert a surgeon to anychange in the delivery of drugs. For example, a beeping tone or flashinglight that increases in frequency as the rate of drug delivery increasesmay be used to alert the surgeon.

The two divisions of the autonomic nervous system that regulate theheart have opposite functions. First, the adrenergic or sympatheticnervous system increases heart rate by releasing epinephrine andnorepinephrine. Second, the parasympathetic system also known as thecholinergic nervous system or the vagal nervous system decreases heartrate by releasing acetylcholine. Catecholamines such as norepinephrine(also called noradrenaline) and epinephrine (also called adrenaline) areagonists for beta-adrenergic receptors. An agonist is a stimulantbiomolecule or agent that binds to a receptor.

Beta-adrenergic receptor blocking agents compete with beta-adrenergicreceptor stimulating agents for available beta-receptor sites. Whenaccess to beta-receptor sites are blocked by receptor blocking agents,also known as beta-adrenergic blockade, the chronotropic or heart rate,inotropic or contractility, and vasodilator responses to receptorstimulating agents are decreased proportionately. Therefore,beta-adrenergic receptor blocking agents are agents that are capable ofblocking beta-adrenergic receptor sites.

Since beta-adrenergic receptors are concerned with contractility andheart rate, stimulation of beta-adrenergic receptors, in general,increases heart rate, the contractility of the heart and the rate ofconduction of electrical impulses through the AV node and the conductionsystem.

Drugs, drug formulations and/or drug compositions that may be usedaccording to this invention may include any naturally occurring orchemically synthesized (synthetic analogues) beta-adrenergic receptorblocking agents. Beta-adrenergic receptor blocking agents orβ-adrenergic blocking agents are also known as beta-blockers orβ-blockers and as class II antiarrhythmics.

The term “beta-blocker” appearing herein may refer to one or more agentsthat antagonize the effects of beta-stimulating catecholamines byblocking the catecholamines from binding to the beta-receptors. Examplesof beta-blockers include, but are not limited to, acebutolol,alprenolol, atenolol, betantolol, betaxolol, bevantolol, bisoprolol,carterolol, celiprolol, chlorthalidone, esmolol, labetalol, metoprolol,nadolol, penbutolol, pindolol, propranolol, oxprenolol, sotalol,teratolo, timolol and combinations, mixtures and/or salts thereof.

The effects of administered beta-blockers may be reversed byadministration of beta-receptor agonists, e.g., dobutamine orisoproterenol.

The parasympathetic or cholinergic system participates in control ofheart rate via the sinoatrial (SA) node, where it reduces heart rate.Other cholinergic effects include inhibition of the AV node and aninhibitory effect on contractile force. The cholinergic system actsthrough the vagal nerve to release acetylcholine, which, in turn,stimulates cholinergic receptors. Cholinergic receptors are also knownas muscarinic receptors. Stimulation of the cholinergic receptorsdecreases the formation of cAMP. Stimulation of cholinergic receptorsgenerally has an opposite effect on heart rate compared to stimulationof beta-adrenergic receptors. For example, beta-adrenergic stimulationincreases heart rate, whereas cholinergic stimulation decreases it. Whenvagal tone is high and adrenergic tone is low, there is a marked slowingof the heart (sinus bradycardia). Acetylcholine effectively reduces theamplitude, rate of increase and duration of the SA node actionpotential. During vagal nerve stimulation, the SA node does not arrest.Rather, pacemaker function may shift to cells that fire at a slowerrate. In addition, acetylcholine may help open certain potassiumchannels thereby creating an outward flow of potassium ions andhyperpolarization. Acetylcholine also slows conduction through the AVnode.

Drugs, drug formulations and/or drug compositions that may be usedaccording to this invention may include any naturally occurring orchemically synthesized (synthetic analogues) cholinergic agent. The term“cholinergic agent” appearing herein may refer to one or morecholinergic receptor modulators or agonists. Examples of cholinergicagents include, but are not limited to, acetylcholine, carbachol(carbamyl choline chloride), bethanechol, methacholine, arecoline,norarecoline and combinations, mixtures and/or salts thereof.

Drugs, drug formulations and/or drug compositions that may be usedaccording to this invention may include any naturally occurring orchemically synthesized cholinesterase inhibitor. The term“cholinesterase inhibitor” appearing herein may refer to one or moreagents that prolong the action of acetylcholine by inhibiting itsdestruction or hydrolysis by cholinesterase. Cholinesterase inhibitorsare also known as acetylcholinesterase inhibitors. Examples ofcholinesterase inhibitors include, but are not limited to, edrophonium,neostigmine, neostigmine methylsulfate, pyridostigmine, tacrine andcombinations, mixtures and/or salts thereof.

There are ion-selective channels within certain cell membranes. Theseion selective channels include calcium channels, sodium channels and/orpotassium channels. Therefore, other drugs, drug formulations and/ordrug compositions that may be used according to this invention mayinclude any naturally occurring or chemically synthesized calciumchannel blocker. Calcium channel blockers inhibit the inward flux ofcalcium ions across cell membranes of arterial smooth muscle cells andmyocardial cells. Therefore, the term “calcium channel blocker”appearing herein may refer to one or more agents that inhibit or blockthe flow of calcium ions across a cell membrane. The calcium channel isgenerally concerned with the triggering of the contractile cycle.Calcium channel blockers are also known as calcium ion influxinhibitors, slow channel blockers, calcium ion antagonists, calciumchannel antagonist drugs and as class IV antiarrhythmics. A commonlyused calcium channel blocker is verapamil.

Administration of a calcium channel blocker, e.g., verapamil, generallyprolongs the effective refractory period within the AV node and slows AVconduction in a rate-related manner, since the electrical activitythrough the AV node depends significantly upon the influx of calciumions through the slow channel. A calcium channel blocker has the abilityto slow a patient's heart rate, as well as produce AV block. Examples ofcalcium channel blockers include, but are not limited to, amiloride,amlodipine, bepridil, diltiazem, felodipine, isradipine, mibefradil,nicardipine, nifedipine (dihydropyridines), nickel, nimodinpine,nisoldipine, nitric oxide (NO), norverapamil and verapamil andcombinations, mixtures and/or salts thereof. Verapamil and diltiazem arevery effective at inhibiting the AV node, whereas drugs of thenifedipine family have a lesser inhibitory effect on the AV node. Nitricoxide (NO) indirectly promotes calcium channel closure. NO may be usedto inhibit contraction. NO may also be used to inhibit sympatheticoutflow, lessen the release of norepinephrine, cause vasodilation,decrease heart rate and decrease contractility. In the SA node,cholinergic stimulation leads to formation of NO.

Other drugs, drug formulations and/or drug compositions that may be usedaccording to this invention may include any naturally occurring orchemically synthesized sodium channel blocker. Sodium channel blockersare also known as sodium channel inhibitors, sodium channel blockingagents, rapid channel blockers or rapid channel inhibitors.Antiarrhythmic agents that inhibit or block the sodium channel are knownas class I antiarrhythmics, examples include, but are not limited to,quinidine and quinidine-like agents, lidocaine and lidocaine-likeagents, tetrodotoxin, encainide, flecainide and combinations, mixturesand/or salts thereof. Therefore, the term “sodium channel blocker”appearing herein may refer to one or more agents that inhibit or blockthe flow of sodium ions across a cell membrane or remove the potentialdifference across a cell membrane. For example, the sodium channel mayalso be totally inhibited by increasing the extracellular potassiumlevels to depolarizing hyperkalemic values, which remove the potentialdifference across the cell membrane. The result is inhibition of cardiaccontraction with cardiac arrest (cardioplegia). The opening of thesodium channel (influx of sodium) is for swift conduction of theelectrical impulse throughout the heart.

Other drugs, drug formulations and/or drug compositions that may be usedaccording to this invention may include any naturally occurring orchemically synthesized potassium channel agent. The term “potassiumchannel agent” appearing herein may refer to one or more agents thatimpact the flow of potassium ions across the cell membrane. There aretwo major types of potassium channels. The first type of channel isvoltage-gated and the second type is ligand-gated.Acetylcholine-activated potassium channels, which are ligand-gatedchannels, open in response to vagal stimulation and the release ofacetylcholine. Opening of the potassium channel causeshyperpolarization, which decreases the rate at which the activationthreshold is reached. Adenosine is one example of a potassium channelopener. Adenosine slows conduction through the AV node. Adenosine, abreakdown product of adenosine triphosphate, inhibits the AV node andatria. In atrial tissue, adenosine causes the shortening of the actionpotential duration and causes hyperpolarization. In the AV node,adenosine has similar effects and also decreases the action potentialamplitude and the rate of increase of the action potential. Adenosine isalso a direct vasodilator by its actions on the adenosine receptor onvascular smooth muscle cells. In addition, adenosine acts as a negativeneuromodulator, thereby inhibiting release of norepinephrine. Class IIIantiarrhythmic agents also known as potassium channel inhibitorslengthen the action potential duration and refractoriness by blockingthe outward potassium channel to prolong the action potential.Amiodarone and d-sotalol are both examples of class III antiarrhythmicagents.

Potassium is the most common component in cardioplegic solutions. Highextracellular potassium levels reduce the membrane resting potential.Opening of the sodium channel, which normally allows rapid sodium influxduring the upstroke of the action potential, is therefore inactivatedbecause of a reduction in the membrane resting potential.

Drugs, drug formulations and/or drug compositions that may be usedaccording to this invention may comprise one or more of any naturallyoccurring or chemically synthesized beta-blocker, cholinergic agent,cholinesterase inhibitor, calcium channel blocker, sodium channelblocker, potassium channel agent, adenosine, adenosine receptor agonist,adenosine deaminase inhibitor, dipyridamole, monoamine oxidaseinhibitor, digoxin, digitalis, lignocaine, bradykinin agents,serotoninergic agonist, antiarrythmic agents, cardiac glycosides, localanesthetics and combinations or mixtures thereof. Digitalis and digoxinboth inhibit the sodium pump. Digitalis is a natural inotrope derivedfrom plant material, while digoxin is a synthesized inotrope.Dipyridamole inhibits adenosine deaminase, which breaks down adenosine.Drugs, drug formulations and/or drug compositions capable of reversiblysuppressing autonomous electrical conduction at the SA and/or AV node,while still allowing the heart to be electrically paced to maintaincardiac output may be used according to this invention.

Beta-adrenergic stimulation or administration of calcium solutions maybe used to reverse the effects of a calcium channel blocker such asverapamil. Agents that promote heart rate and/or contraction may be usedin the present invention. For example, dopamine, a naturalcatecholamine, is known to increase contractility. Positive inotropesare agents that specifically increase the force of contraction of theheart. Glucagon, a naturally occurring hormone, is known to increaseheart rate and contractility. Glucagon may be used to reverse theeffects of a beta-blocker since its effects bypass the beta receptor.Forskolin is known to increase heart rate and contractility. Asmentioned earlier, epinephrine and norepinephrine naturally increaseheart rate and contractility. Thyroid hormone, phosphodiesteraseinhibitors and prostacyclin, a prostaglandin, are also known to increaseheart rate and contractility. In addition, methylxanthines are known toprevent adenosine from interacting with its cell receptors.

The drug delivery device may include a vasodilative delivery componentand/or a vasoconstrictive delivery component. Both delivery componentsmay be any suitable means for delivering vasodilative and/orvasoconstrictive drugs to a site of a medical procedure. For example,the drug delivery device may be a system for delivering a vasodilativespray and/or a vasoconstrictive spray. The drug delivery device may be asystem for delivering a vasodilative cream and/or a vasoconstrictivecream. The drug delivery device may be a system for delivering anyvasodilative formulation such as an ointment or medicament etc. and/orany vasoconstrictive formulation such as an ointment or medicament etc.or any combination thereof.

The drug delivery device may comprise a catheter, such as a drugdelivery catheter or a guide catheter, for delivering a vasodilativesubstance followed by a vasoconstrictive substance. A drug deliverycatheter may include an expandable member, e.g., a low-pressure balloon,and a shaft having a distal portion, wherein the expandable member isdisposed along the distal portion. A catheter for drug delivery maycomprise one or more lumens and may be delivered endovascularly viainsertion into a blood vessel, e.g., an artery such as a femoral,radial, subclavian or coronary artery. The catheter can be guided into adesired position using various guidance techniques, e.g., flouroscopicguidance and/or a guiding catheter or guide wire techniques. In oneembodiment, one catheter may be used to deliver both a vasodilativecomponent and a vasoconstrictive component. The drug delivery device maybe a patch, such as a transepicardial patch that slowly releases drugsdirectly into the myocardium, a cannula, a pump and/or a hypodermicneedle and syringe assembly. The drug delivery device may be aniontophoretic drug delivery device placed on the heart.

A vasodilative component may comprise one or more vasodilative drugs inany suitable formulation or combination. Examples of vasodilative drugsinclude, but are not limited to, a vasodilator, an organic nitrate,isosorbide mononitrate, a mononitrate, isosorbide dinitrate, adinitrate, nitroglycerin, a trinitrate, minoxidil, sodium nitroprusside,hydralazine hydrochloride, nitric oxide, nicardipine hydrochloride,fenoldopam mesylate, diazoxide, enalaprilat, epoprostenol sodium, aprostaglandin, milrinone lactate, a bipyridine and a dopamine D1-likereceptor agonist, stimulant or activator. The vasodilative component mayinclude a pharmaceutically acceptable carrier or solution in anappropriate dosage.

A vasoconstrictive component may comprise one or more suitablevasoconstrictive drugs in any suitable formulation or combination.Examples of vasoconstrictive drugs include, but are not limited to, avasoconstrictor, a sympathomimetic, methoxamine hydrochloride,epinephrine, midodrine hydrochloride, desglymidodrine, and analpha-receptor agonist, stimulant or activator. The vasoconstrictivecomponent may include a pharmaceutically acceptable carrier or solutionin an appropriate dosage

System 10 may include energy source 50. Energy source 50 may comprise acontrol unit. Tissue-engaging device 20 may be permanently ornon-permanently attached to energy source 50. Energy source 50 maysupply electrical energy, radiofrequency (RF) energy, laser energy,thermal energy, microwave energy, ultrasound energy and/or any otherappropriate type of energy that may be used for the desired medicalprocedure, for example to ablate tissue. Energy source 50 may be poweredby AC current, DC current or it may be battery powered either by adisposable or re-chargeable battery. Energy source 50 may be used tocoordinate the various elements of system 10. For example, energy source50 may be configured to synchronize activation and deactivation ofsuction source 20 with the delivery of energy.

Energy source 50 may incorporate a controller or processor. For example,the controller may process sensed information from a sensor. Thecontroller may store and/or process such information before, duringand/or after a medical procedure. For example, the patient's tissuetemperature may be sensed, stored and processed prior to and during amedical procedure.

Energy source 50 may be used to control the energy supplied to one ormore energy transfer elements of tissue-engaging device 20. Energysource 50 may also gather and process information from one or moresensors. This information may be used to adjust energy levels and times.Energy source 50 may incorporate one or more switches to facilitateregulation of the various system components by the surgeon. One exampleof such a switch is a foot pedal. A switch may also be, for example, ahand switch, or a voice-activated switch comprising voice-recognitiontechnologies. A switch may be physically wired to energy source 50 or itmay be a remote control switch. A switch may be incorporated in or onone of the surgeon's instruments, such as surgical site retractor, e.g.,a sternal or rib retractor, tissue-engaging device 20, or any otherlocation easily and quickly accessed by the surgeon. Energy source 50may also include a display. Energy source 50 may also include othermeans of indicating the status of various components to the surgeon suchas a numerical display, gauges, a monitor display or audio feedback.

Energy source 50 may incorporate a cardiac stimulator and/or cardiacmonitor. For example, electrodes used to stimulate or monitor the heartmay be incorporated into tissue-engaging device 20. Energy source 50 maycomprise a surgeon-controlled switch for cardiac stimulation ormonitoring, as discussed earlier. Cardiac stimulation may comprisecardiac pacing and/or cardiac defibrillation. Energy source 50 mayincorporate a cardiac mapping device for mapping the electrical signalsof the heart.

A visual and/or audible signal used to alert a surgeon to the completionor resumption of energy delivery, suction, sensing, monitoring,stimulation and/or delivery of fluids, drugs and/or cells may beincorporated into energy source 50. For example, a beeping tone orflashing light that increases in frequency as the energy deliveredincreases.

System 10 may include sensor 60. Sensor 60 may be incorporated intotissue-engaging device 20 or it may be incorporated into a separatedevice. A separate sensor device may be positioned and used, forexample, through a thoracotomy, through a sternotomy, percutaneously,transvenously, arthroscopically, endoscopically, for example, through apercutaneous port, through a stab wound or puncture, through a smallincision, for example, in the chest, in the groin, in the abdomen, inthe neck or in the knee, or in combinations thereof.

Sensor 60 may comprise one or more switches, e.g., a surgeon-controlledswitch. One or more switches may be incorporated in or on a sensordevice or any other location easily and quickly accessed by the surgeonfor regulation of sensor 60 by the surgeon. A switch may be, forexample, a hand switch, a foot switch, or a voice-activated switchcomprising voice-recognition technologies. A switch may be physicallywired to sensor 60 or it may be a remote control switch.

Sensor 60 may include a visual and/or audible signal used to alert asurgeon to any change in the measured parameter, for example, tissuetemperature, cardiac hemodynamics or ischemia. A beeping tone orflashing light may be used to alert the surgeon that a change hasoccurred in the parameter sensed.

Sensor 60 may comprise one or more temperature-sensitive elements, suchas a thermocouple, to allow a surgeon to monitor temperature changes ofa patient's tissue. Alternatively, sensor 60 may sense and/or monitorvoltage, amperage, wattage and/or impedance. For example, an ECG sensormay allow a surgeon to monitor the hemodynamics of a patient during aheart positioning procedure. The heart may become hemodynamicallycompromised during positioning and while in a non-physiologicalposition. Alternatively, sensor 60 may be any suitable blood gas sensorfor measuring the concentration or saturation of a gas in the blood ortissues. For example, sensor 60 may be a sensor for measuring theconcentration or saturation of oxygen or carbon dioxide in the blood ortissues. Alternatively, sensor 60 may be any suitable sensor formeasuring blood pressure or flow, for example a Doppler ultrasoundsensor system, or a sensor for measuring hematocrit (HCT) levels.

Alternatively sensor 60 may be a biosensor, for example, comprising animmobilized biocatalyst, enzyme, immunoglobulin, bacterial, mammalian orplant tissue, cell and/or subcellular fraction of a cell. For example,the tip of a biosensor may comprise a mitochondrial fraction of a cell,thereby providing the sensor with a specific biocatalytic activity.

Sensor 60 may be based on potentiometric technology or fiber optictechnology. For example, the sensor may comprise a potentiometric orfiber optic transducer. An optical sensor may be based on either anabsorbance or fluorescence measurement and may include an UV, a visibleor an IR light source.

Sensor 60 may be used to detect naturally detectable propertiesrepresentative of one or more characteristics, e.g., chemical, physical,mechanical, thermal, electrical or physiological, of system 10 and/or apatient's bodily tissues or fluids. For example, naturally detectableproperties of patient's bodily tissues or fluids may include pH, fluidflow, electrical current, impedance, temperature, pressure, tension,components of metabolic processes, chemical concentrations, for example,the absence or presence of specific peptides, proteins, enzymes, gases,ions, etc. Naturally detectable properties of system 10 may include, forexample, pressure, tension, stretch, fluid flow, electrical, mechanical,chemical and/or thermal. For example, sensor 60 may be used to sense,monitor and/or control suction or vacuum delivered from suction source30. Sensor 60 may be used to measure suction between device 20 andtissue. Sensor 60 may be used to sense, monitor and/or control fluiddelivered from fluid source 40. Sensor 60 may be used to sense, monitorand/or control energy delivered from energy source 50.

Sensor 60 may include one or more imaging systems, camera systemsoperating in UV, visible, or IR range; electrical sensors; voltagesensors; current sensors; piezoelectric sensors; electromagneticinterference (EMI) sensors; photographic plates, polymer-metal sensors;charge-coupled devices (CCDs); photo diode arrays; chemical sensors,electrochemical sensors; pressure sensors, vibration sensors, sound wavesensors; magnetic sensors; UV light sensors; visible light sensors; IRlight sensors; radiation sensors; flow sensors; temperature sensors; orany other appropriate or suitable sensor.

Sensor 60 may be incorporated into tissue-engaging device 20 or sensor60 may be placed or used at a location differing from the location oftissue-engaging device 20. For example, sensor 60 may be placed incontact with the inside surface of a patient's heart whiletissue-engaging device 20 is placed or used on the outside surface ofthe patient's heart.

Tissue-engaging device 20, suction source 30, fluid source 40, energysource 50 and/or processor 70 may be slaved to sensor 60. For example,tissue-engaging device 20 may be designed to automatically adjustsuction if sensor 60 measures a predetermined sensor value, e.g., aparticular suction value.

Sensor 60 may include a visual and/or audible signal used to alert asurgeon to any change in the one or more characteristics the sensor issensing and/or monitoring. For example, a beeping tone or flashing lightthat increases in frequency as tissue temperature rises may be used toalert the surgeon.

System 10 may include processor 70. Processor 70 may receive andpreferably interpret the signal from sensor 60. Processor 70 maycomprise software and/or hardware. Processor 70 may comprise fuzzylogic. A suitable amplifier may amplify signals from sensor 60 beforereaching processor 70. The amplifier may be incorporated into processor70. Alternatively the amplifier may be incorporated into sensor 60 ortissue-engaging device 20. Alternatively, the amplifier may be aseparate device. Processor 70 may be a device separate fromtissue-engaging device 20, suction source 30, fluid source 40, energysource 50 or sensor 60. Processor 70 may be incorporated intotissue-engaging device 20, suction source 30, fluid source 40, energysource 50 or sensor 60. Processor 70 may control the energy deliveredfrom the energy source 50. For example, a signal of a first intensityfrom sensor 60 may indicate that the energy level from energy source 50should be lowered; a signal of a different intensity may indicate thatenergy source 50 should be turned off. Preferably, processor 70 may beconfigured so that it may automatically raise or lower the suctiondelivered to device 20 from suction source 30, the fluids delivered todevice 20 from fluid source 40 and/or the energy delivered to device 20from energy source 50. Alternatively, the control of suction source 30,fluid source 40 and/or energy source 50 based on output from processor70 may be manual.

Processor 70 may include a visual display or monitor, such as, forexample, a LCD or CRT monitor, to display various amounts and types ofinformation. By software control, the user may choose to display theinformation in a number of ways. The monitor may show, for example, acurrently sensed parameter, e.g., temperature. The monitor may also lockand display the maximum sensed value achieved. Sensed information may bedisplayed to the user in any suitable manner, such as for example,displaying a virtual representation of tissue-engaging device 20 on themonitor.

Alternatively, the monitor may display the voltage corresponding to thesignal emitted from sensor 60. This signal corresponds in turn to theintensity of a sensed parameter at the target tissue site. Therefore avoltage level of 2 would indicate that the tissue was, for example,hotter than when the voltage level was 1. In this example, a user wouldmonitor the voltage level and, if it exceeded a certain value, wouldturn off or adjust the energy source 50.

The display of processor 70 may alternatively be located ontissue-engaging device 20, suction source 30, fluid source 40, energysource 50 and/or sensor 60. An indicator, such as an LED light, may bepermanently or removeably incorporated into tissue-engaging device 20,suction source 30, fluid source 40, energy source 50 and/or sensor 60.The indicator may receive a signal from sensor 60 indicating that thetissue had reached an appropriate value, for example temperature. Inresponse, the indicator may turn on, change color, grow brighter orchange in any suitable manner to indicate that the flow of energy fromenergy source 50 should be modified or halted. The indicator may also belocated on tissue-engaging device 20, suction source 30, fluid source40, energy source 50, sensor 60 and/or may be located on anotherlocation visible to the user.

Alternatively, the processor 70 may include an audio device thatindicates to the user that the delivery of suction, fluids and/or energyshould be halted or adjusted. Such an audio device may be, for example,a speaker that broadcasts a sound (for example, a beep) that increasesin intensity, frequency or tone as a parameter sensed by sensor 60increases. The user may adjust, for example, turn down or turn offenergy source 50 when the sound emitted reaches a given volume or level.In another embodiment, the audio device may also give an audible signal(such as the message “turn off energy source”), for example, when aparameter sensed by sensor 60 reaches a certain level. Such an audiodevice may be located on tissue-engaging device 20, suction source 30,fluid source 40, energy source 50 and/or sensor 60. The audio device mayalso be a separate device.

Processor 70 may comprise one or more switches, e.g., asurgeon-controlled switch. One or more switches may be incorporated inor on processor 70 or any other location easily and quickly accessed bythe surgeon for regulation of processor 70 by the surgeon. A switch maybe, for example, a hand switch, a foot switch, or a voice-activatedswitch comprising voice-recognition technologies. A switch may bephysically wired to processor 70 or it may be a remote control switch.

In one embodiment of the present invention, system 10 may include anillumination device (not shown). The illumination device may compriseone or more light sources and/or illuminating materials, e.g.,glow-in-the-dark materials. For example, the tissue-engaging head ofdevice 20 may comprise one or more glow-in-the-dark materials. Theillumination device may be based on fluorescence technologies. Theillumination device may comprise fiber optic technologies; for example afiber optic conduit may deliver light from a remote light source to anarea adjacent tissue-engaging device 20 for illumination of a surgicalsite.

The illumination device may comprise a light pipe, for example, toilluminate the tissue-engaging head of device 20 and/or the surgicalfield adjacent device 20. A transparent, semi-transparent or translucenttissue-engaging head may be illuminated merely by placement of the endof a light pipe or other light source adjacent the tissue-engaging headof device 20.

The illumination source may be powered by AC current, DC current, or itmay be battery powered either by a disposable or re-chargeable battery.The illumination source may provide UV, IR and/or visible light. Theillumination source may be a laser. The illumination device may beincorporated into tissue-engaging device 20 or it may be incorporatedinto a separate device. A separate illumination device may be positionedand used, for example, through a thoracotomy, through a sternotomy,percutaneously, transvenously, arthroscopically, endoscopically, forexample, through a percutaneous port, through a stab wound or puncture,through a small incision, for example, in the chest, in the groin, inthe abdomen, in the neck or in the knee, or in combinations thereof.

The illumination device may comprise one or more switches, e.g., asurgeon-controlled switch. One or more switches may be incorporated inor on the illumination device or any other location easily and quicklyaccessed by the surgeon for regulation of the illumination device by thesurgeon. A switch may be, for example, a hand switch, a foot switch, ora voice-activated switch comprising voice-recognition technologies. Aswitch may be physically wired to the illumination device or it may be aremote control switch.

Tissue-engaging device 20, suction source 30, fluid source 40, energysource 50, sensor 60, processor 70, drug delivery device and/orillumination device may be slaved to a robotic system or a roboticsystem may be slaved to tissue-engaging device 20, suction source 30,fluid source 40, energy source 50, sensor 60, processor 70, drugdelivery device and/or illumination device. Computer- andvoice-controlled robotic systems that position and maneuver endoscopesand/or other surgical instruments for performing microsurgicalprocedures through small incisions may be used by the surgeon to performprecise and delicate maneuvers. These robotic systems may allow thesurgeon to perform a variety of microsurgical procedures. In general,robotic systems may include head-mounted displays which integrate 3-Dvisualization of surgical anatomy and related diagnostic and monitoringdata, miniature high resolution 2-D and 3-D digital cameras, a computer,a high power light source and a standard video monitor.

A medical procedure wherein system 10 may be used may be non-invasive,minimally invasive and/or invasive. The medical procedure may entail aport-access approach, a partially or totally endoscopic approach, asternotomy approach or a thoracotomy approach. The medical procedure mayinclude the use of various robotic or imaging systems. The medicalprocedure may be surgery on the heart. Alternatively, the medicalprocedure may be surgery performed on another organ of the body.

The term “medical procedure” may mean any one or more medical orsurgical procedures such as, for example cardiac surgery, performed withor without cardiopulmonary bypass (CPB) circuits, heart valve repair,heart valve replacement, MAZE procedures, transmyocardialrevascularization (TMR), CABG procedures, anastomosis procedures,non-surgical procedures, endoscopic procedures, non-invasive procedures,invasive procedures, port-access procedures, fluoroscopic procedures,beating heart surgery, vascular surgery, neurosurgery, electrophysiologyprocedures, diagnostic and therapeutic procedures, ablation procedures,ablation of arrhythmias, endovascular procedures, treatment of one ormore organs and/or vessels, treatment of the heart, aneurysm repair,aortic aneurysm repairs, imaging procedures of the heart and greatvessels, CAT scan procedures, MRI procedures, cardiograms,pharmacological therapies, drug delivery procedures, delivery ofbiological agents, gene therapies, cellular therapies, cancer therapies,radiation therapies, genetic, cellular, tissue and/or organ manipulationor transplantation procedures, coronary angioplasty procedures,placement or delivery of coated or noncoated stents, LVAD procedures,lead placement procedures, placement of cardiac reinforcement devices,placement of cardiac assistance devices, atherectomy procedures,atherosclerotic plaque manipulation and/or removal procedures, emergencyprocedures, cosmetic procedures, reconstructive surgical procedures,biopsy procedures, autopsy procedures, surgical training procedures,birthing procedures, congenital repair procedures, and medicalprocedures that require positioning one or more organs and/or tissues.

In one embodiment of the present invention, as shown in FIG. 28, system10 includes multiple tissue-engaging devices 20 each comprising atissue-engaging head 221, an articulating support arm 222 and a mountingclamp 223. Both devices 20 are coupled to a suction source 30 thatprovides a negative pressure of about 400 mm Hg. In this embodiment,suction source 30 is shown coupled to processor 70. In this embodiment,both tissue-engaging devices 20 are clamped to retractor 150 that isfixed to a patient's chest. The head of the first device 20 is placed onthe apex or left ventricle of the patient's heart. Suction is providedto the first tissue-engaging device via tubing 900. The head of thefirst device 20 is allowed to firmly engage or grasp the surface of theheart. The heart is positioned into the desired orientation. Forexample, the heart may be positioned for providing access to lateraland/or posterior vessels of the heart. Articulating arm 222 of the firstdevice 20 is locked into position when the heart is in the desiredorientation via knob 950 thereby positioning and supporting the heart.In this embodiment, the head of the second device 20 is placed on thesurface of the patient's heart adjacent a coronary artery. Suction isprovided to the second tissue-engaging device via tubing 900. The headof the second device 20 is allowed to firmly engage or grasp the surfaceof the heart. Articulating arm 222 of the second device 20 is lockedinto position via knob 951 thereby immobilizing the area of tissueadjacent the head of the second device 20.

As shown in FIG. 28, tissue-engaging head of first device 20 maycomprise one or more electrodes connected via leads 191 to energy source50. In this embodiment, energy source 50 is shown coupled to processor70. The electrodes may be used for pacing and/or defibrillation of thepatient's heart. Tissue-engaging head of first device 20 may alsocomprise one or more sensors for sensing the patient's ECG, for example,connected to processor 70 via conductor 952. Second device 20 maycomprise one or more fluid openings for delivery of fluid from fluidsource 40. Fluid source 40 is coupled to second device 20 via tubing953. In this embodiment, fluid source 40 is shown coupled to processor70. As shown in this embodiment of the present invention, processor 70is coupled to a manual foot switch 954. In addition, processor 70comprises multiple displays 955 and knobs 956 for providing feedback andcontrol.

As shown in FIG. 28, endotracheal tube 957 comprising one or moreelectrodes may be positioned in a patient's trachea. Endotracheal tube957 may be connected to a breathing regulator (not shown in FIG. 28).The electrodes of endotracheal tube 957 may be used to stimulate thepatient's vagal nerve thereby slowing or stopping the patient's heart.The patient may be given drugs as described above to help stop thebeating of the heart and/or to prevent “escape” beats. Following vagalstimulation, the heart may be paced via first device 20. The electrodesof endotracheal tube 957 may be coupled to processor 70 and energysource 50 via leads 191.

In one embodiment of the present invention, a nerve stimulator may beused to electrically manipulate cardiac rhythm by stimulating the vagusnerve. This vagal stimulation may produce asystole (slowing or stoppingof the heart's beating.) Once this induced asystole is stopped, i.e.once the vagal stimulation is stopped, the heart may be allowed toreturn to its usual cardiac rhythm. Alternatively, the heart may bepaced, thereby maintaining a normal cardiac output. Vagal stimulation,alone or in combination with electrical pacing, may be used selectivelyand intermittently to allow a surgeon to perform a medical procedure,such as a CABG procedure, and yet still allow the heart itself to supplyblood circulation to the body while one or more tissue-engaging devices20 are used to position and/or stabilize an area of the heart. Forexample, stimulation of the vagus nerve in order to temporarily andintermittently slow or stop the heart is described in U.S. Pat. No.6,006,134 entitled “Method and Device for Electronically Controlling theBeating of a Heart Using Venous Electrical Stimulation of Nerve Fibers”,Dec. 21, 1999, to Hill and Junkman and in U.S. patent application Ser.No. 09/670,441 filed Sep. 26, 2000, Ser. No. 09/669,960 filed Sep. 26,2000, Ser. No. 09/670,370 filed Sep. 26, 2000, Ser. No. 09/669,961 filedSep. 26, 2000, Ser. No. 09/669,355 filed Sep. 26, 2000 and Ser. No.09/670,369 filed Sep. 26, 2000. These patents and patent applicationsare assigned to Medtronic, Inc. and are incorporated herein byreference.

FIG. 29 shows a flow diagram of one embodiment of the present invention.The patient is prepared for a medical procedure at 700. Once the patientis prepared, the heart is engaged and positioned using tissue-engagingdevice 20 of system 10 (Block 705). Once the heart is positioned in adesired orientation, a nerve that controls the beating of the heart isstimulated to slow down or stop the contractions of the heart (Block708). Such a nerve may be for example a vagal nerve. During this time,one or more of a variety of pharmacological agents or drugs may bedelivered to the patient. These drugs may produce reversible asystole ofa heart while maintaining the ability of the heart to be electricallypaced. Other drugs may be administered for a variety of functions andpurposes as described above. Drugs may be administered at the beginningof the procedure, intermittently during the procedure, continuouslyduring the procedure or following the procedure.

Typically, vagal nerve stimulation prevents the heart from contracting.This non-contraction must then be followed by periods without vagalnerve stimulation during which the heart is allowed to contract, andblood flow is restored throughout the body. Following initial slowing orstopping of the heart, a medical procedure, e.g., CABG, ablation, leadplacement and/or other procedure as described above, is begun (Block710). Following a brief interval of nerve stimulation while a medicalprocedure is performed, nerve stimulation is ceased (Block 713) and theheart is allowed to contract. A cardiac stimulator or pacemaker may beused to cause the heart to contract or the heart may be free to beat onits own (Blocks 722 and 724). In one embodiment of the presentinvention, tissue-engaging device 20 includes one or more electrodes,which may be used for pacing, coupled to energy source 50. Processor 70may control both cardiac and nerve stimulation. For example, processor70 may automatically proceed to block 713 to cease nerve stimulation. Inaddition, processor 70 may automatically begin cardiac stimulation. Ifthe medical procedure needs to continue or a new medical procedure is tobe performed, the heart may be repositioned if necessary or desired atBlock 748.

FIG. 30 shows a flow diagram of one embodiment of the present invention.The patient is prepared for a medical procedure at 700. At this point,the heart may be engaged and positioned by tissue-engaging device 20 ofsystem 10, for example, to provide access to the posterior or backsideof the heart (Block 705). As seen in FIG. 29, heart positioning mayoccur throughout the entire procedure in a continuous or intermittentmanner. At Block 710, a medical procedure, e.g., a CABG procedurecomprising the use of a distal anastomotic device or other medicalprocedure as mentioned above, is begun. At Block 717, it is determinedif the heart needs to be repositioned. For example, upon completion of afirst anastomosis, e.g., via delivery of a distal anastomotic device,the heart may be repositioned to provide better access for creation of asecond anastomosis. Again at Block 725, it is determined if the heartneeds to be repositioned. For example, upon completion of a secondanastomosis, e.g., via delivery of a distal anastomotic device, theheart may again be repositioned to provide access for creation of athird anastomosis. During the medical procedure fluids may be deliveredto tissue-engaging device 20 from fluid source 40. Processor 70 maycontrol the delivery of fluids from fluid source 40.

FIG. 31 shows a flow diagram of one embodiment of the present invention.The patient is prepared for a medical procedure at 700. At this point,the heart may be engaged and positioned by tissue-engaging device 20 ofsystem 10, for example, to provide access to the posterior or backsideof the heart (Block 705). As seen in FIG. 29, heart positioning mayoccur throughout the entire procedure in a continuous or intermittentmanner. At Block 706, the patient's hemodynamic condition may be sensedand monitored, for example, the patient's ECG may be sensed andmonitored by sensor 60 and processor 70. At Block 707, it is determinedif the heart needs to be repositioned. Following repositioning of theheart (Block 723), if necessary, a medical procedure is performed atBlock 710. The medical procedure, e.g., a CABG procedure comprising theuse of a distal anastomotic device or other medical procedure asmentioned above, is begun. At Block 711, it is again determined if theheart needs to be repositioned. For example, upon completion of a firstanastomosis, e.g., via delivery of a distal anastomotic device, theheart may be repositioned to provide better access for creation of asecond anastomosis located in a different location from the firstanastomosis. Following repositioning of the heart (Block 723), ifnecessary, the medical procedure is continued at Block 720.

System 10 may be used for creating space in a surgical field. Forexample, tissue-engaging device 20 may be used to grasp and position thepericardium away from the surface of the heart thereby creating spacebetween the surface of the heart and the pericardium. This type ofprocedure may be termed “tenting”. Tissue-engaging device 20 may be usedto grasp and position a heart away from a rib cage, for example in anendoscopic procedure, thereby creating space for a surgeon to workbetween the heart and the rib cage. Tissue-engaging device 20 may beused to grasp and position a heart away from other adjacent or nearbyorgans thereby creating space for a surgeon to work.

In one embodiment of the present invention, as shown in FIG. 32, themedical procedure may include the use of one or more tissuestabilization devices, e.g., the “OCTOPUS 3”™ which is marketed byMedtronic, Inc., Minneapolis, Minn. USA. See, also, tissue stabilizersdisclosed in U.S. Pat. Nos. 5,836,311; 5,927,284 and 6,015,378,co-assigned U.S. patent application Ser. No. 09/396,047, filed Sep. 15,1999; and Ser. No. 09/678,203, filed Oct. 2, 2000, and European PatentPublication No. EP 0 993 806. These patents are assigned to Medtronic,Inc. and are incorporated herein by reference. As shown in FIG. 32,tissue-engaging device 20 of system 10 may be used in a medicalprocedure, e.g., a CABG procedure, in combination with a tissuestabilizer 990. As shown in FIG. 32, both devices may be attached toretractor 150 fixed to a patient's chest.

In one method of the present invention, as shown in FIG. 33, the medicalprocedure may include the use of one or more tissue ablation devices.For example, see tissue ablation devices disclosed in U.S. patentapplication Ser. No. 09/844,220 filed Apr. 26, 2001, now U.S. Pat. No.6,584,320, Ser. No. 09/844,221 filed Apr. 26, 2001 and Ser. No.09/843,897 filed Apr. 26, 2001, now U.S. Pat. No. 6,558,382. Thesepatent applications are assigned to Medtronic, Inc. and are incorporatedherein by reference. As shown in FIG. 33, tissue-engaging device 20 ofsystem 10 may be used in a medical procedure, e.g., an ablationprocedure, in combination with a tissue ablation device 995. Device 20may be attached to retractor 150 fixed to a patient's chest. Tissueablation devices may be used to ablate tissue located within a bodycavity, such as the endocardial or epicardial tissue of the heart. Otherbody organ tissue, such as the liver, lungs or kidney, may also bepositioned and ablated. Other tissue types may be ablated includingskin, muscle or even cancerous tissue or abnormal tissue growth.

It will be appreciated by those skilled in the art that while theinvention has been described above in connection with particularembodiments and examples, the invention is not necessarily so limited,and that numerous other embodiments, examples, uses, modifications anddepartures from the embodiments, examples and uses are intended to beencompassed by the claims attached hereto. The entire disclosure of eachpatent and publication cited herein is incorporated by reference, as ifeach such patent or publication were individually incorporated byreference herein.

1. A method of performing an electrode placement procedure on apatient's heart, comprising: providing a first tissue contact devicecomprising: a rigid tissue contact member sized and shaped to fitthrough a small incision in a region of the patient's chest; anillumination device coupled to the rigid tissue contact member; amaneuvering apparatus having a rigid shaft and a handle; and a remotelyactuatable joint moveably coupling the tissue contact member to themaneuvering apparatus; introducing the rigid contact member of the firsttissue contact device to the patient's thoracic cavity through a smallincision in the patient's chest; providing illumination; actuating thejoint remotely from outside the thoracic cavity of the patient;maneuvering the tissue contact member of the first tissue contact deviceto position pericardium away from a surface of the heart to create spacebetween the surface of the heart and the pericardium using the firsttissue contact device, the space providing exposure of the heart;providing a second tissue contact device comprising: a rigid tissuecontact member having an ablation electrode; and a maneuvering apparatushaving a shaft and a handle coupled to the rigid contact member;introducing the rigid contact member of the second tissue contact deviceinto the thoracic cavity of the patient through an incision in theregion of the patient's chest; and placing the ablation electrode on orwithin the exposed heart.
 2. The method of claim 1 further comprising:stimulating the heart in order to adjust the beating of the heart. 3.The method of claim 2 wherein the heart is stimulated by pacing.
 4. Themethod of claim 2 wherein the heart is stimulated by defibrillation. 5.The method of claim 1 further comprising: sensing the electrical signalsof the heart.
 6. The method of claim 1 further comprising: administeringat least one drug to the heart.
 7. The method of claim 6 wherein thedrug is selected from the group consisting of: a beta-blocker, acholinergic agent, a cholinesterase inhibitor, a calcium channelblocker, a sodium channel blocker, a potassium channel agent, adenosine,an adenosine receptor agonist, an adenosine deaminase inhibitor,dipyridaniole, a monoamine oxidase inhibitor, digoxin, digitalis,lignocaine, a bradykinin agent, a serotoninergic agonist, anantiarrythmic agent, a cardiac glycoside, a local anesthetic, atropine,a calcium solution, an agent that promotes heart rate, an agent thatpromotes heart contractions, dopamine, a catecholamine, an inotropeglucagon, a hormone, forskolin, epinephrine, norepinephrine, thyroidhormone, a phosphodiesterase inhibitor, prostacyclin, prostaglandin anda methylxanthine.
 8. The method of claim 1 further comprising:delivering one or more fluids to the heart.
 9. The method of claim 8wherein the one or more fluids comprises at least one diagnostic agent,therapeutic agent or biological agent.
 10. The method of claim 1 furthercomprising: evaluating the hemodynamic condition of the heart with asensor.
 11. The method of claim 1, further comprising: providing atleast one fluid adjacent the electrode.
 12. The method of claim 1further comprising: stimulating a nerve to adjust the beating of theheart to a first condition.
 13. The method of claim 12 wherein the firstcondition is a stopped condition.
 14. The method of claim 12 wherein thefirst condition is a slowed condition.
 15. The method of claim 12further comprising: adjusting stimulation of the nerve to adjust thebeating of the heart to a second condition.
 16. The method of claim 15further comprising: stimulating the nerve a subsequent time in order tore-adjust the beating of the heart to the first condition.
 17. Themethod of claim 15 wherein the stimulation is stopped to achieve thesecond condition.
 18. The method of claim 15 wherein the secondcondition is a beating condition.
 19. The method of claim 15 furthercomprising: stimulating the heart in order to adjust the beating of theheart to the second condition.
 20. The method of claim 19 wherein theheart is stimulated by pacing.
 21. The method of claim 12 wherein thenerve is a vagal nerve.
 22. The method of claim 1 wherein the secondtissue contact device is a suction assisted device.
 23. The method ofclaim 1 further comprising: providing at least one fluid adjacent thesecond tissue contact device.
 24. The method of claim 23 wherein thefluid is provided adjacent the ablation electrode.
 25. The method ofclaim 1 wherein the tissue contact member of the first or second tissuecontact device comprises one or more hooks.
 26. The method of claim 1wherein the tissue contact member of the first or second tissue contactdevice comprises one or more clamps.
 27. The method of claim 1 whereinthe tissue contact member of the first or second tissue contact devicecomprises one or more barbs.
 28. The method of claim 1 wherein thetissue contact member of the first or second tissue contact devicecomprises a magnet.
 29. The method of claim 1 wherein the joint is apivot that allows the tissue contact member of the first tissue contactdevice to rotate relative to the rigid shaft.
 30. The method of claim 1wherein the joint is a hinge.
 31. The method of claim 1 wherein thetissue contact member of the first or second tissue contact device isshaped to conform to a surface of tissue.
 32. The method of claim 1wherein the tissue contact member of the first or second tissue contactdevice is shapeable to conform to a surface of tissue.
 33. The method ofclaim 1 wherein the illumination device includes a light source.
 34. Themethod of claim 1 wherein the illumination device includes anilluminating material.
 35. The method of claim 1 wherein theillumination device includes a fiber optic conduit.
 36. The method ofclaim 1 wherein the illumination device includes a light pipe.
 37. Themethod of claim 1 wherein the illumination device includes a battery.38. The method of claim 1 wherein the illumination device provides UVlight.
 39. The method of claim 1 wherein the illumination deviceprovides IR light.
 40. The method of claim 1 wherein the illuminationdevice provides visible light.
 41. The method of claim 1 wherein theillumination device includes a laser.
 42. The method of claim 1 whereinthe illumination device includes a switch.
 43. The method of claim 1wherein the first tissue contact device includes a LED.
 44. The methodof claim 1 wherein the first or second tissue contact device isremovably coupled to a flexible hose during the procedure.
 45. Themethod of claim 1 wherein the first or second tissue contact device isremovably coupled to a flexible tube during the procedure.
 46. Themethod of claim 1 wherein the first or second tissue contact device isremovably coupled to a flexible catheter during the procedure.
 47. Themethod of claim 1 wherein the first or second tissue contact member isguided into a desired position.
 48. The method of claim 1 wherein thefirst or second tissue contact member comprises one or more sensors. 49.The method of claim 1 further comprising ablating a tissue of the heartto perform at least a portion of a MAZE procedure.
 50. The method ofclaim 1 wherein the step of placing the ablation electrode on the heartincludes placing the ablation electrode on epicardial tissue of theheart.
 51. The method of claim 1 further comprising the step of guidingthe first or second tissue contact device into a desired position usinga guidance technique.
 52. The method of claim 51 wherein the guidancetechnique is a flouroscopic guidance technique.
 53. A method ofperforming an electrode placement procedure on a patient's heart,comprising: providing a first tissue contact device comprising: a rigidtissue contact member sized and shaped to fit through a small incisionin a region of the patient's chest; an illumination device coupled tothe rigid tissue contact member; a maneuvering apparatus having a rigidshaft and a handle; and a remotely actuatable joint moveably couplingthe tissue contact member to the maneuvering apparatus; introducing therigid contact member of the first tissue contact device to the patient'sthoracic cavity through a small incision in the patient's chest;providing illumination; actuating the joint remotely from outside thethoracic cavity of the patient; maneuvering the tissue contact member ofthe first tissue contact device to position pericardium away from asurface of the heart to create space between the surface of the heartand the pericardium using the first tissue contact device, the spaceproviding exposure of the heart; providing a second tissue contactdevice comprising: a rigid tissue contact member having an energytransfer electrode; and a maneuvering apparatus having a shaft and ahandle coupled to the rigid contact member; introducing the rigidcontact member of the second tissue contact device into the thoraciccavity of the patient through an incision in the region of the patient'schest; and placing the electrode on or within the exposed heart.
 54. Themethod of claim 53 further comprising stimulating the heart in order toadjust the beating of the heart.
 55. The method of claim 53 wherein theheart is stimulated by pacing.
 56. The method of claim 53 wherein theheart is stimulated by defibrillation.
 57. The method of claim 53further comprising sensing the electrical signals of the heart.
 58. Themethod of claim 53 further comprising administering at least one drug tothe heart.
 59. The method of claim 58 wherein the drug is abeta-blocker, a cholinergic agent, a cholinesterase inhibitor, a calciumchannel blocker, a sodium channel blocker, a potassium channel agent,adenosine, an adenosine receptor agonist, an adenosine deaminaseinhibitor, dipyridamole, a monoamine oxidase inhibitor, digoxin,digitalis, lignocaine, a bradykinin agent, a serotoninergic agonist, anantiarrythmic agent, a cardiac glycoside, a local anesthetic, atropine,a calcium solution, an agent that promotes heart rate, an agent thatpromotes heart contractions, dopamine, a catecholamine, an inotropeglucagon, a hormone, forskolin, epinephrine, norepinephrine, thyroidhormone, a phosphodiesterase inhibitor, prostacyclin, prostaglandin or amethylxanthine.
 60. The method of claim 53 further comprising deliveringone or more fluids to the heart.
 61. The method of claim 60 wherein thefluid comprises a diagnostic agent, a therapeutic agent, a biologicalagent, or a combination thereof.
 62. The method of claim 53 furthercomprising evaluating the hemodynamic condition of the heart with asensor.
 63. The method of claim 53, further comprising providing atleast one fluid adjacent the electrode.
 64. The method of claim 53further comprising stimulating a nerve to adjust the beating of theheart to a first condition.
 65. The method of claim 64 wherein the firstcondition is a stopped condition.
 66. The method of claim 64 wherein thefirst condition is a slowed condition.
 67. The method of claim 64further comprising adjusting stimulation of the nerve to adjust thebeating of the heart to a second condition.
 68. The method of claim 67further comprising stimulating the nerve a subsequent time in order tore-adjust the beating of the heart to the first condition.
 69. Themethod of claim 67 wherein the stimulation is stopped to achieve thesecond condition.
 70. The method of claim 67 wherein the secondcondition is a beating condition.
 71. The method of claim 67 furthercomprising stimulating the heart in order to adjust the beating of theheart to the second condition.
 72. The method of claim 71 wherein theheart is stimulated by pacing.
 73. The method of claim 64 wherein thenerve is a vagal nerve.
 74. The method of claim 53 wherein the secondtissue contact device is a suction assisted device.
 75. The method ofclaim 53 further comprising providing at least one fluid adjacent thesecond tissue contact device.
 76. The method of claim 75 wherein thefluid is provided adjacent the ablation electrode.
 77. The method ofclaim 53 wherein the tissue contact member of the first or second tissuecontact device comprises one or more hooks.
 78. The method of claim 53wherein the tissue contact member of the first or second tissue contactdevice comprises one or more clamps.
 79. The method of claim 53 whereinthe tissue contact member of the first or second tissue contact devicecomprises one or more barbs.
 80. The method of claim 53 wherein thetissue contact member of the first or second tissue contact devicecomprises a magnet.
 81. The method of claim 53 wherein the joint is apivot that allows the tissue contact member of the first tissue contactdevice to rotate relative to the rigid shaft.
 82. The method of claim 53wherein the joint is a hinge.
 83. The method of claim 53 wherein thetissue contact member of the first or second tissue contact device isshaped to conform to a surface of tissue.
 84. The method of claim 53wherein the tissue contact member of the first or second tissue contactdevice is shapeable to conform to a surface of tissue.
 85. The method ofclaim 53 wherein the illumination device includes a light source. 86.The method of claim 53 wherein the illumination device includes anilluminating material.
 87. The method of claim 53 wherein theillumination device includes a fiber optic conduit.
 88. The method ofclaim 53 wherein the illumination device includes a light pipe.
 89. Themethod of claim 53 wherein the illumination device includes a battery.90. The method of claim 53 wherein the illumination device provides UVlight.
 91. The method of claim 53 wherein the illumination deviceprovides IR light.
 92. The method of claim 53 wherein the illuminationdevice provides visible light.
 93. The method of claim 53 wherein theillumination device includes a laser.
 94. The method of claim 53 whereinthe illumination device includes a switch.
 95. The method of claim 53wherein the first tissue contact device includes a LED.
 96. The methodof claim 53 wherein the first or second tissue contact device isremovably coupled to a flexible hose during the procedure.
 97. Themethod of claim 53 wherein the first or second tissue contact device isremovably coupled to a flexible tube during the procedure.
 98. Themethod of claim 53 wherein the first or second tissue contact device isremovably coupled to a flexible catheter during the procedure.
 99. Themethod of claim 53 wherein the first or second tissue contact member isguided into a desired position.
 100. The method of claim 53 wherein thefirst or second tissue contact member comprises one or more sensors.101. The method of claim 100 further comprising ablating a tissue of theheart to perform at least a portion of a MAZE procedure.
 102. The methodof claim 53 wherein the step of placing the electrode on the heartincludes placing the electrode on epicardial tissue of the heart. 103.The method of claim 53 further comprising the step of guiding the firstor second tissue contact device into a desired position using a guidancetechnique.
 104. The method of claim 103 wherein the guidance techniquecomprises flouroscopy.